ExplorEnz: Search Results

References:

1.	Kühn, A., Yu, S. and Giffhorn, F. Catabolism of 1,5-anhydro-D-fructose in Sinorhizobium morelense S-30.7.5: discovery, characterization, and overexpression of a new 1,5-anhydro-D-fructose reductase and its application in sugar analysis and rare sugar synthesis. Appl. Environ. Microbiol. 72 (2006) 1248–1257. [DOI] [PMID: 16461673]
2.	Dambe, T.R., Kühn, A.M., Brossette, T., Giffhorn, F. and Scheidig, A.J. Crystal structure of NADP(H)-dependent 1,5-anhydro-D-fructose reductase from Sinorhizobium morelense at 2.2 Å resolution: construction of a NADH-accepting mutant and its application in rare sugar synthesis. Biochemistry 45 (2006) 10030–10042. [DOI] [PMID: 16906761]

[EC 1.1.1.292 created 2007]

1.1.1.385

Accepted name:

dihydroanticapsin dehydrogenase

Reaction:

L-dihydroanticapsin + NAD⁺ = L-anticapsin + NADH + H⁺

For diagram of bacilysin biosynthesis, click here

Glossary:

L-dihydroanticapsin = 3-[(1R,2S,5R,6S)-5-hydroxy-7-oxabicyclo[4.1.0]hept-2-yl]-L-alanine
L-anticapsin = 3-[(1R,2S,6R)-5-oxo-7-oxabicyclo[4.1.0]hept-2-yl]-L-alanine

Other name(s):

BacC; ywfD (gene name)

Systematic name:

L-dihydroanticapsin:NAD⁺ oxidoreductase

Comments:

The enzyme, characterized from the bacterium Bacillus subtilis, is involved in the biosynthesis of the nonribosomally synthesized dipeptide antibiotic bacilysin, composed of L-alanine and L-anticapsin.

Links to other databases:

References:

1.	Parker, J.B. and Walsh, C.T. Action and timing of BacC and BacD in the late stages of biosynthesis of the dipeptide antibiotic bacilysin. Biochemistry 52 (2013) 889–901. [DOI] [PMID: 23317005]

[EC 1.1.1.385 created 2015]

1.2.3.1

Accepted name:

aldehyde oxidase

Reaction:

an aldehyde + H₂O + O₂ = a carboxylate + H₂O₂

Other name(s):

quinoline oxidase; retinal oxidase

Systematic name:

aldehyde:oxygen oxidoreductase

Comments:

Contains molybdenum, [2Fe-2S] centres and FAD. The enzyme from liver exhibits a broad substrate specificity, and is involved in the metabolism of xenobiotics, including the oxidation of N-heterocycles and aldehydes and the reduction of N-oxides, nitrosamines, hydroxamic acids, azo dyes, nitropolycyclic aromatic hydrocarbons, and sulfoxides [4,6]. The enzyme is also responsible for the oxidation of retinal, an activity that was initially attributed to a distinct enzyme (EC 1.2.3.11, retinal oxidase) [5,7].

Links to other databases:

BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9029-07-6

References:

1.	Gordon, A.H., Green, D.E. and Subrahmanyan, V. Liver aldehyde oxidase. Biochem. J. 34 (1940) 764–774. [PMID: 16747217]
2.	Knox, W.E. The quinine-oxidizing enzyme and liver aldehyde oxidase. J. Biol. Chem. 163 (1946) 699–711. [PMID: 20985642]
3.	Mahler, H.R., Mackler, B., Green, D.E. and Bock, R.M. Studies on metalloflavoproteins. III. Aldehyde oxidase: a molybdoflavoprotein. J. Biol. Chem. 210 (1954) 465–480. [PMID: 13201608]
4.	Krenitsky, T.A., Neil, S.M., Elion, G.B. and Hitchings, G.H. A comparison of the specificities of xanthine oxidase and aldehyde oxidase. Arch. Biochem. Biophys. 150 (1972) 585–599. [DOI] [PMID: 5044040]
5.	Tomita, S., Tsujita, M. and Ichikawa, Y. Retinal oxidase is identical to aldehyde oxidase. FEBS Lett. 336 (1993) 272–274. [DOI] [PMID: 8262244]
6.	Yoshihara, S. and Tatsumi, K. Purification and characterization of hepatic aldehyde oxidase in male and female mice. Arch. Biochem. Biophys. 338 (1997) 29–34. [DOI] [PMID: 9015384]
7.	Huang, D.-Y., Furukawa, A. and Ichikawa, Y. Molecular cloning of retinal oxidase/aldehyde oxidase cDNAs from rabbit and mouse livers and functional expression of recombinant mouse retinal oxidase cDNA in Escherichia coli. Arch. Biochem. Biophys. 364 (1999) 264–272. [DOI] [PMID: 10190983]
8.	Uchida, H., Kondo, D., Yamashita, A., Nagaosa, Y., Sakurai, T., Fujii, Y., Fujishiro, K., Aisaka, K. and Uwajima, T. Purification and characterization of an aldehyde oxidase from Pseudomonas sp. KY 4690. FEMS Microbiol. Lett. 229 (2003) 31–36. [DOI] [PMID: 14659539]

[EC 1.2.3.1 created 1961, modified 2002, modified 2004, modified 2012]

1.2.7.12

Accepted name:

formylmethanofuran dehydrogenase

Reaction:

a formylmethanofuran + H₂O + 2 oxidized ferredoxin [iron-sulfur] cluster = CO₂ + a methanofuran + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H⁺

For diagram of methane biosynthesis, click here

Glossary:

methanofuran a = 4-[4-(2-{[(4R*,5S*)-4,5,7-tricarboxyheptanoyl]-γ-L-glutamyl-γ-L-glutamylamino}ethyl)phenoxymethyl]furan-2-ylmethanamine

Other name(s):

formylmethanofuran:acceptor oxidoreductase

Systematic name:

formylmethanofuran:ferredoxin oxidoreductase

Comments:

Contains a molybdopterin cofactor and numerous [4Fe-4S] clusters. In some organisms an additional subunit enables the incorporation of tungsten when molybdenum availability is low. The enzyme catalyses a reversible reaction in methanogenic archaea, and is involved in methanogenesis from CO₂ as well as the oxidation of coenzyme M to CO₂. The reaction is endergonic, and is driven by coupling with the soluble CoB-CoM heterodisulfide reductase via electron bifurcation.

Links to other databases:

BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 119940-12-4

References:

1.	Karrasch, M., Börner, G., Enssle, M. and Thauer, R.K. The molybdoenzyme formylmethanofuran dehydrogenase from Methanosarcina barkeri contains a pterin cofactor. Eur. J. Biochem. 194 (1990) 367–372. [DOI] [PMID: 2125267]
2.	Bertram, P.A., Schmitz, R.A., Linder, D. and Thauer, R.K. Tungstate can substitute for molybdate in sustaining growth of Methanobacterium thermoautotrophicum. Identification and characterization of a tungsten isoenzyme of formylmethanofuran dehydrogenase. Arch. Microbiol. 161 (1994) 220–228. [PMID: 8161283]
3.	Bertram, P.A., Karrasch, M., Schmitz, R.A., Bocher, R., Albracht, S.P. and Thauer, R.K. Formylmethanofuran dehydrogenases from methanogenic Archaea. Substrate specificity, EPR properties and reversible inactivation by cyanide of the molybdenum or tungsten iron-sulfur proteins. Eur. J. Biochem. 220 (1994) 477–484. [DOI] [PMID: 8125106]
4.	Vorholt, J.A. and Thauer, R.K. The active species of ’CO₂’ utilized by formylmethanofuran dehydrogenase from methanogenic Archaea. Eur. J. Biochem. 248 (1997) 919–924. [DOI] [PMID: 9342247]
5.	Meuer, J., Kuettner, H.C., Zhang, J.K., Hedderich, R. and Metcalf, W.W. Genetic analysis of the archaeon Methanosarcina barkeri Fusaro reveals a central role for Ech hydrogenase and ferredoxin in methanogenesis and carbon fixation. Proc. Natl. Acad. Sci. USA 99 (2002) 5632–5637. [DOI] [PMID: 11929975]
6.	Kaster, A.K., Moll, J., Parey, K. and Thauer, R.K. Coupling of ferredoxin and heterodisulfide reduction via electron bifurcation in hydrogenotrophic methanogenic archaea. Proc. Natl. Acad. Sci. USA 108 (2011) 2981–2986. [DOI] [PMID: 21262829]
7.	Wagner, T., Ermler, U. and Shima, S. The methanogenic CO₂ reducing-and-fixing enzyme is bifunctional and contains 46 [4Fe-4S] clusters. Science 354 (2016) 114–117. [PMID: 27846502]

[EC 1.2.7.12 created 1992 as EC 1.2.99.5, transferred 2017 to EC 1.2.7.12]

1.2.99.5

Transferred entry:

formylmethanofuran dehydrogenase. Now EC 1.2.7.12, formylmethanofuran dehydrogenase

[EC 1.2.99.5 created 1992, deleted 2017]

1.3.1.3

Accepted name:

Δ⁴-3-oxosteroid 5β-reductase

Reaction:

a 3-oxo-5β-steroid + NADP⁺ = a 3-oxo-Δ⁴-steroid + NADPH + H⁺

For diagram of cholesterol catabolism (rings a, B and c), click here

Other name(s):

3-oxo-Δ⁴-steroid 5β-reductase; 5β-reductase; androstenedione 5β-reductase; cholestenone 5β-reductase; cortisone 5β-reductase; cortisone β-reductase; cortisone Δ⁴-5β-reductase; steroid 5β-reductase; testosterone 5β-reductase; Δ⁴-3-ketosteroid 5β-reductase; Δ⁴-5β-reductase; Δ⁴-hydrogenase; 4,5β-dihydrocortisone:NADP⁺ Δ⁴-oxidoreductase; 3-oxo-5β-steroid:NADP⁺ Δ⁴-oxidoreductase; 5β-cholestan-3-one:NADP⁺ 4,5-oxidoreductase

Systematic name:

3-oxo-5β-steroid:NADP⁺ 4,5-oxidoreductase

Comments:

The enzyme from human efficiently catalyses the reduction of progesterone, androstenedione, 17α-hydroxyprogesterone and testosterone to 5β-reduced metabolites; it can also act on aldosterone, corticosterone and cortisol, but to a lesser extent [8]. The bile acid intermediates 7α,12α-dihydroxy-4-cholesten-3-one and 7α-hydroxy-4-cholesten-3-one can also act as substrates [9].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9029-08-7

References:

1.	Forchielli, E. and Dorfman, R.I. Separation of Δ⁴-5α- and Δ⁴-5β-hydrogenases from rat liver homogenates. J. Biol. Chem. 223 (1956) 443–448. [PMID: 13376613]
2.	Brown-Grant, K., Forchielli, E. and Dorfman, R.I. The Δ⁴-hydrogenases of guinea pig adrenal gland. J. Biol. Chem. 235 (1960) 1317–1320. [PMID: 13805063]
3.	Levy, H.R. and Talalay, P. Enzymatic introduction of double bonds into steroid ring A. J. Am. Chem. Soc. 79 (1957) 2658–2659. [DOI]
4.	Tomkins, G.M. The enzymatic reduction of Δ⁴-3-ketosteroids. J. Biol. Chem. 225 (1957) 13–24. [PMID: 13416214]
5.	Sugimoto, Y., Yoshida, M. and Tamaoki, B. Purification of 5β-reductase from hepatic cytosol fraction of chicken. J. Steroid Biochem. 37 (1990) 717–724. [PMID: 2278855]
6.	Furuebisu, M., Deguchi, S. and Okuda, K. Identification of cortisone 5β-reductase as Δ⁴-3-ketosteroid 5β-reductase. Biochim. Biophys. Acta 912 (1987) 110–114. [DOI] [PMID: 3828348]
7.	Okuda, A. and Okuda, K. Purification and characterization of Δ⁴-3-ketosteroid 5β-reductase. J. Biol. Chem. 259 (1984) 7519–7524. [PMID: 6736016]
8.	Charbonneau, A. and The, V.L. Genomic organization of a human 5β-reductase and its pseudogene and substrate selectivity of the expressed enzyme. Biochim. Biophys. Acta 1517 (2001) 228–235. [DOI] [PMID: 11342103]
9.	Kondo, K.H., Kai, M.H., Setoguchi, Y., Eggertsen, G., Sjöblom, P., Setoguchi, T., Okuda, K.I. and Björkhem, I. Cloning and expression of cDNA of human Δ⁴-3-oxosteroid 5β-reductase and substrate specificity of the expressed enzyme. Eur. J. Biochem. 219 (1994) 357–363. [PMID: 7508385]

[EC 1.3.1.3 created 1961 (EC 1.3.1.23 created 1972, incorporated 2005), modified 2005]

1.3.1.62

Accepted name:

pimeloyl-CoA dehydrogenase

Reaction:

pimeloyl-CoA + NAD⁺ = 6-carboxyhex-2-enoyl-CoA + NADH + H⁺

Glossary:

pimelic acid = heptanedioic acid

Systematic name:

pimeloyl-CoA:NAD⁺ oxidoreductase

Comments:

Involved in the benzoate degradation (anaerobic) pathway in bacteria.

Links to other databases:

BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, CAS registry number: 276682-23-6

References:

1.	Gallus, C. and Schink, B. Anaerobic degradation of pimelate by newly isolated denitrifying bacteria. Microbiology 140 (1994) 409–416. [DOI] [PMID: 8180704]

[EC 1.3.1.62 created 2000]

1.3.3.4

Accepted name:

protoporphyrinogen oxidase

Reaction:

protoporphyrinogen IX + 3 O₂ = protoporphyrin IX + 3 H₂O₂

For diagram of the later stages of porphyrin biosynthesis, click here

Other name(s):

protoporphyrinogen IX oxidase; protoporphyrinogenase; PPO; Protox; HemG; HemY

Systematic name:

protoporphyrinogen-IX:oxygen oxidoreductase

Comments:

This is the last common enzyme in the biosynthesis of chlorophylls and heme [8]. Two isoenzymes exist in plants: one in plastids and the other in mitochondria. This is the target enzyme of phthalimide-type and diphenylether-type herbicides [8]. The enzyme from oxygen-dependent species contains FAD [9]. Also slowly oxidizes mesoporphyrinogen IX.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 53986-32-6

References:

1.	Poulson, R. The enzymic conversion of protoporphyrinogen IX to protoporphyrin IX in mammalian mitochondria. J. Biol. Chem. 251 (1976) 3730–3733. [PMID: 6461]
2.	Poulson, R. and Polglase, W.J. The enzymic conversion of protoporphyrinogen IX to protoporphyrin IX. Protoporphyrinogen oxidase activity in mitochondrial extracts of Saccharomyces cerevisiae. J. Biol. Chem. 250 (1975) 1269–1274. [PMID: 234450]
3.	Dailey, H.A. and Dailey, T.A. Protoporphyrinogen oxidase of Myxococcus xanthus. Expression, purification, and characterization of the cloned enzyme. J. Biol. Chem. 271 (1996) 8714–8718. [DOI] [PMID: 8621504]
4.	Wang, K.F., Dailey, T.A. and Dailey, H.A. Expression and characterization of the terminal heme synthetic enzymes from the hyperthermophile Aquifex aeolicus. FEMS Microbiol. Lett. 202 (2001) 115–119. [DOI] [PMID: 11506917]
5.	Corrigall, A.V., Siziba, K.B., Maneli, M.H., Shephard, E.G., Ziman, M., Dailey, T.A., Dailey, H.A., Kirsch, R.E. and Meissner, P.N. Purification of and kinetic studies on a cloned protoporphyrinogen oxidase from the aerobic bacterium Bacillus subtilis. Arch. Biochem. Biophys. 358 (1998) 251–256. [DOI] [PMID: 9784236]
6.	Ferreira, G.C. and Dailey, H.A. Mouse protoporphyrinogen oxidase. Kinetic parameters and demonstration of inhibition by bilirubin. Biochem. J. 250 (1988) 597–603. [PMID: 2451512]
7.	Dailey, T.A. and Dailey, H.A. Human protoporphyrinogen oxidase: expression, purification, and characterization of the cloned enzyme. Protein Sci. 5 (1996) 98–105. [DOI] [PMID: 8771201]
8.	Che, F.S., Watanabe, N., Iwano, M., Inokuchi, H., Takayama, S., Yoshida, S. and Isogai, A. Molecular characterization and subcellular localization of protoporphyrinogen oxidase in spinach chloroplasts. Plant Physiol. 124 (2000) 59–70. [PMID: 10982422]
9.	Dailey, T.A. and Dailey, H.A. Identification of an FAD superfamily containing protoporphyrinogen oxidases, monoamine oxidases, and phytoene desaturase. Expression and characterization of phytoene desaturase of Myxococcus xanthus. J. Biol. Chem. 273 (1998) 13658–13662. [DOI] [PMID: 9593705]

[EC 1.3.3.4 created 1978, modified 2003]

1.3.3.15

Accepted name:

coproporphyrinogen III oxidase (coproporphyrin-forming)

Reaction:

coproporphyrinogen III + 3 O₂ = coproporphyrin III + 3 H₂O₂

Other name(s):

hemY (gene name)

Systematic name:

coproporphyrinogen-III:oxygen oxidoreductase (coproporphyrin-forming)

Comments:

Contains FAD. The enzyme, present in Gram-positive bacteria, participates in heme biosynthesis. It can also catalyse the reaction of EC 1.3.3.4, protoporphyrinogen oxidase, at a lower level.

Links to other databases:

References:

1.	Hansson, M. and Hederstedt, L. Bacillus subtilis HemY is a peripheral membrane protein essential for protoheme IX synthesis which can oxidize coproporphyrinogen III and protoporphyrinogen IX. J. Bacteriol. 176 (1994) 5962–5970. [DOI] [PMID: 7928957]
2.	Corrigall, A.V., Siziba, K.B., Maneli, M.H., Shephard, E.G., Ziman, M., Dailey, T.A., Dailey, H.A., Kirsch, R.E. and Meissner, P.N. Purification of and kinetic studies on a cloned protoporphyrinogen oxidase from the aerobic bacterium Bacillus subtilis. Arch. Biochem. Biophys. 358 (1998) 251–256. [DOI] [PMID: 9784236]
3.	Qin, X., Sun, L., Wen, X., Yang, X., Tan, Y., Jin, H., Cao, Q., Zhou, W., Xi, Z. and Shen, Y. Structural insight into unique properties of protoporphyrinogen oxidase from Bacillus subtilis. J. Struct. Biol. 170 (2010) 76–82. [DOI] [PMID: 19944166]
4.	Dailey, H.A., Gerdes, S., Dailey, T.A., Burch, J.S. and Phillips, J.D. Noncanonical coproporphyrin-dependent bacterial heme biosynthesis pathway that does not use protoporphyrin. Proc. Natl. Acad. Sci. USA 112 (2015) 2210–2215. [DOI] [PMID: 25646457]

[EC 1.3.3.15 created 2016]

1.3.4.1

Accepted name:

fumarate reductase (CoM/CoB)

Reaction:

fumarate + CoM + CoB = succinate + CoM-S-S-CoB

Glossary:

CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine (deprecated)
CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)

Other name(s):

thiol:fumarate reductase; Tfr

Systematic name:

fumarate CoM:CoB oxidoreductase (succinate-forming)

Comments:

The enzyme, isolated from the archaeon Methanobacterium thermoautotrophicum, is very oxygen sensitive. It cannot use reduced flavins, reduced coenzyme F₄₂₀, or NAD(P)H as an electron donor. Distinct from EC 1.3.1.6 [fumarate reductase (NADH)], EC 1.3.5.1 [succinate dehydrogenase (ubiquinone)], and EC 1.3.5.4 [fumarate reductase (quinol)].

Links to other databases:

References:

1.	Khandekar, S.S. and Eirich, L.D. Purification and characterization of an anabolic fumarate reductase from Methanobacterium thermoautotrophicum. Appl. Environ. Microbiol. 55 (1989) 856–861. [PMID: 2499256]
2.	Heim, S., Kunkel, A., Thauer, R.K. and Hedderich, R. Thiol:fumarate reductase (Tfr) from Methanobacterium thermoautotrophicum. Identification of the catalytic sites for fumarate reduction and thiol oxidation. Eur. J. Biochem. 253 (1998) 292–299. [DOI] [PMID: 9578488]

[EC 1.3.4.1 created 2014 as EC 1.3.98.2, transferred 2014 to EC 1.3.4.1]

1.3.99.14

Accepted name:

cyclohexanone dehydrogenase

Reaction:

cyclohexanone + acceptor = cyclohex-2-enone + reduced acceptor

Other name(s):

cyclohexanone:(acceptor) 2-oxidoreductase

Systematic name:

cyclohexanone:acceptor 2-oxidoreductase

Comments:

2,6-Dichloroindophenol can act as acceptor. The corresponding ketones of cyclopentane and cycloheptane cannot act as donors.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 123516-43-8

References:

1.	Dangel, W., Tschech, A. and Fuchs, G. Enzyme-reactions involved in anaerobic cyclohexanol metabolism by a denitrifying Pseudomonas species. Arch. Microbiol. 152 (1989) 273–279. [PMID: 2505723]

[EC 1.3.99.14 created 1992]

1.4.1.16

Accepted name:

diaminopimelate dehydrogenase

Reaction:

meso-2,6-diaminoheptanedioate + H₂O + NADP⁺ = L-2-amino-6-oxoheptanedioate + NH₃ + NADPH + H⁺

Other name(s):

meso-α,ε-diaminopimelate dehydrogenase; meso-diaminopimelate dehydrogenase

Systematic name:

meso-2,6-diaminoheptanedioate:NADP⁺ oxidoreductase (deaminating)

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 60894-21-5

References:

1.	Misono, H., Togawa, H., Yamamoto, T. and Soda, K. Occurrence of meso-α,ε-diaminopimelate dehydrogenase in Bacillus sphaericus. Biochem. Biophys. Res. Commun. 72 (1976) 89–93. [DOI] [PMID: 10904]
2.	Misono, H., Togawa, H., Yamamoto, T. and Soda, K. meso-α,ε-Diaminopimelate D-dehydrogenase: distribution and the reaction product. J. Bacteriol. 137 (1979) 22–27. [PMID: 762012]

[EC 1.4.1.16 created 1981]

1.4.1.24

Accepted name:

3-dehydroquinate synthase II

Reaction:

2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate + H₂O + NAD⁺ = 3-dehydroquinate + NH₃ + NADH + H⁺

For diagram of 3-dehydroquinate biosynthesis in archaea, click here

Glossary:

2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate = 2-amino-2,3,7-trideoxy-D-lyxo-hept-6-ulosonate

Other name(s):

DHQ synthase II; MJ1249 (gene name); aroB′ (gene name)

Systematic name:

2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate:NAD⁺ oxidoreductase (deaminating)

Comments:

The enzyme, which was isolated from the archaeon Methanocaldococcus jannaschii, plays a key role in an alternative pathway for the biosynthesis of 3-dehydroquinate (DHQ), an intermediate of the canonical pathway for the biosynthesis of aromatic amino acids. The enzyme catalyses a two-step reaction - an oxidative deamination, followed by cyclization.

Links to other databases:

References:

1.	White, R.H. L-Aspartate semialdehyde and a 6-deoxy-5-ketohexose 1-phosphate are the precursors to the aromatic amino acids in Methanocaldococcus jannaschii. Biochemistry 43 (2004) 7618–7627. [DOI] [PMID: 15182204]

[EC 1.4.1.24 created 2012]

1.5.1.54

Accepted name:

methylenetetrahydrofolate reductase (NADH)

Reaction:

5-methyltetrahydrofolate + NAD⁺ = 5,10-methylenetetrahydrofolate + NADH + H⁺

For diagram of reaction, click here and for its place in C₁ metabolism, click here

Other name(s):

metF (gene name); 5,10-methylenetetrahydrofolic acid reductase (ambiguous); 5,10-CH₂-H₄folate reductase (ambiguous); methylenetetrahydrofolate (reduced riboflavin adenine dinucleotide) reductase; 5,10-methylenetetrahydrofolate reductase (ambiguous); methylenetetrahydrofolate reductase (ambiguous); N⁵,10-methylenetetrahydrofolate reductase (ambiguous); 5,10-methylenetetrahydropteroylglutamate reductase (ambiguous); N⁵,N¹⁰-methylenetetrahydrofolate reductase (ambiguous); methylenetetrahydrofolic acid reductase (ambiguous); 5-methyltetrahydrofolate:(acceptor) oxidoreductase (incorrect); 5,10-methylenetetrahydrofolate reductase (FADH₂) (ambiguous)

Systematic name:

5-methyltetrahydrofolate:NAD⁺ oxidoreductase

Comments:

A flavoprotein (FAD). The enzyme, found in plants and some bacteria, catalyses the reversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate using NADH as the electron donor. It play an important role in folate metabolism by regulating the distribution of one-carbon moieties between cellular methylation reactions and nucleic acid synthesis. These proteins either contain a C-terminal domain that does not mediate allosteric regulation (as in plants) or lack this domain entirely (as in Escherichia coli). As a result, the plant enzymes are not inhibited by S-adenosyl-L-methionine, unlike other eukaryotic enzymes, and catalyse a reversible reaction. cf. EC 1.5.1.53, methylenetetrahydrofolate reductase (NADPH); EC 1.5.1.20, methylenetetrahydrofolate reductase [NAD(P)H]; and EC 1.5.7.1, methylenetetrahydrofolate reductase (ferredoxin).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 71822-25-8

References:

1.	Wohlfarth, G., Geerligs, G. and Diekert, G. Purification and properties of a NADH-dependent 5,10-methylenetetrahydrofolate reductase from Peptostreptococcus productus. Eur. J. Biochem. 192 (1990) 411–417. [DOI] [PMID: 2209595]
2.	Sheppard, C.A., Trimmer, E.E. and Matthews, R.G. Purification and properties of NADH-dependent 5,10-methylenetetrahydrofolate reductase (MetF) from Escherichia coli. J. Bacteriol. 181 (1999) 718–725. [PMID: 9922232]
3.	Guenther, B.D., Sheppard, C.A., Tran, P., Rozen, R., Matthews, R.G. and Ludwig, M.L. The structure and properties of methylenetetrahydrofolate reductase from Escherichia coli suggest how folate ameliorates human hyperhomocysteinemia. Nat. Struct. Biol. 6 (1999) 359–365. [DOI] [PMID: 10201405]
4.	Roje, S., Wang, H., McNeil, S.D., Raymond, R.K., Appling, D.R., Shachar-Hill, Y., Bohnert, H.J. and Hanson, A.D. Isolation, characterization, and functional expression of cDNAs encoding NADH-dependent methylenetetrahydrofolate reductase from higher plants. J. Biol. Chem. 274 (1999) 36089–36096. [DOI] [PMID: 10593891]
5.	Bertsch, J., Oppinger, C., Hess, V., Langer, J.D. and Muller, V. Heterotrimeric NADH-oxidizing methylenetetrahydrofolate reductase from the acetogenic bacterium Acetobacterium woodii. J. Bacteriol. 197 (2015) 1681–1689. [DOI] [PMID: 25733614]

[EC 1.5.1.54 created 2021]

1.6.5.2

Accepted name:

NAD(P)H dehydrogenase (quinone)

Reaction:

NAD(P)H + H⁺ + a quinone = NAD(P)⁺ + a hydroquinone

For diagram of the vitamin K cycle, click here

Other name(s):

menadione reductase; phylloquinone reductase; quinone reductase; dehydrogenase, reduced nicotinamide adenine dinucleotide (phosphate, quinone); DT-diaphorase; flavoprotein NAD(P)H-quinone reductase; menadione oxidoreductase; NAD(P)H dehydrogenase; NAD(P)H menadione reductase; NAD(P)H-quinone dehydrogenase; NAD(P)H-quinone oxidoreductase; NAD(P)H: (quinone-acceptor)oxidoreductase; NAD(P)H: menadione oxidoreductase; NADH-menadione reductase; naphthoquinone reductase; p-benzoquinone reductase; reduced NAD(P)H dehydrogenase; viologen accepting pyridine nucleotide oxidoreductase; vitamin K reductase; diaphorase; reduced nicotinamide-adenine dinucleotide (phosphate) dehydrogenase; vitamin-K reductase; NAD(P)H₂ dehydrogenase (quinone); NQO1; QR1; NAD(P)H:(quinone-acceptor) oxidoreductase

Systematic name:

NAD(P)H:quinone oxidoreductase

Comments:

A flavoprotein. The enzyme catalyses a two-electron reduction and has a preference for short-chain acceptor quinones, such as ubiquinone, benzoquinone, juglone and duroquinone [6]. The animal, but not the plant, form of the enzyme is inhibited by dicoumarol.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9032-20-6

References:

1.	di Prisco, G., Casola, L. and Giuditta, A. Purification and properties of a soluble reduced nicotinamide-adenine dinucleotide (phosphate) dehydrogenase from the hepatopancreas of Octopus vulgaris. Biochem. J. 105 (1967) 455–460. [PMID: 4171422]
2.	Giuditta, A. and Strecker, H.J. Purification and some properties of a brain diaphorase. Biochim. Biophys. Acta 48 (1961) 10–19. [DOI] [PMID: 13705804]
3.	Märki, F. and Martius, C. Vitamin K-Reductase, Darsellung und Eigenschaften. Biochem. Z. 333 (1960) 111–135. [PMID: 13765127]
4.	Misaka, E. and Nakanishi, K. Studies on menadione reductase of bakers' yeast. I. Purification, crystallization and some properties. J. Biochem. (Tokyo) 53 (1963) 465–471.
5.	Wosilait, W.D. The reduction of vitamin K₁ by an enzyme from dog liver. J. Biol. Chem. 235 (1960) 1196–1201. [PMID: 13846011]
6.	Sparla, F., Tedeschi, G. and Trost, P. NAD(P)H:(quinone-acceptor) oxidoreductase of tobacco leaves is a flavin mononucleotide-containing flavoenzyme. Plant Physiol. 112 (1996) 249–258. [PMID: 12226388]
7.	Braun, M., Bungert, S. and Friedrich, T. Characterization of the overproduced NADH dehydrogenase fragment of the NADH:ubiquinone oxidoreductase (complex I) from Escherichia coli. Biochemistry 37 (1998) 1861–1867. [DOI] [PMID: 9485311]
8.	Jaiswal, A.K. Characterization and partial purification of microsomal NAD(P)H:quinone oxidoreductases. Arch. Biochem. Biophys. 375 (2000) 62–68. [DOI] [PMID: 10683249]
9.	Li, R., Bianchet, M.A., Talalay, P. and Amzel, L.M. The three-dimensional structure of NAD(P)H:quinone reductase, a flavoprotein involved in cancer chemoprotection and chemotherapy: mechanism of the two-electron reduction. Proc. Natl. Acad. Sci. USA 92 (1995) 8846–8850. [DOI] [PMID: 7568029]

[EC 1.6.5.2 created 1961, transferred 1965 to EC 1.6.99.2, transferred 2005 to EC 1.6.5.2]

1.8.3.1

Accepted name:

sulfite oxidase

Reaction:

sulfite + O₂ + H₂O = sulfate + H₂O₂

Systematic name:

sulfite:oxygen oxidoreductase

Comments:

A molybdohemoprotein.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9029-38-3

References:

1.	Kessel, D.L., Johnston, J.L., Cohen, H.J. and Rajagopalan, K.V. Visualization of hepatic sulfite oxidase in crude tissue preparation by electron paramagnetic resonance spectroscopy. Biochim. Biophys. Acta 334 (1974) 86–96.
2.	MacLeod, R.M., Farkas, W., Fridovitch, I. and Handler, P. Purfication and properties of hepatic sulfite oxidase. J. Biol. Chem. 236 (1961) 1841–1846. [PMID: 13764978]
3.	Tager, J.M. and Rautanen, N. Sulfite oxidation by a plant mitochondrial system. I. Preliminary observations. Biochim. Biophys. Acta 18 (1955) 111–121. [PMID: 13260249]

[EC 1.8.3.1 created 1961]

1.8.4.2

Accepted name:

protein-disulfide reductase (glutathione)

Reaction:

2 glutathione + protein-disulfide = glutathione-disulfide + protein-dithiol

Other name(s):

glutathione-insulin transhydrogenase; insulin reductase; reductase, protein disulfide (glutathione); protein disulfide transhydrogenase; glutathione-protein disulfide oxidoreductase; protein disulfide reductase (glutathione); GSH-insulin transhydrogenase; protein-disulfide interchange enzyme; protein-disulfide isomerase/oxidoreductase; thiol:protein-disulfide oxidoreductase; thiol-protein disulphide oxidoreductase

Systematic name:

glutathione:protein-disulfide oxidoreductase

Comments:

Reduces insulin and some other proteins.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9082-53-5

References:

1.	Katzen, H.M., Tietze, F. and Stetten, D. Further studies on the properties of hepatic glutathione-insulin transhydrogenase. J. Biol. Chem. 238 (1963) 1006–1011. [PMID: 14031343]
2.	Kohnert, K.-D., Hahn, H.-J., Zühlke, H., Schmidt, S. and Fiedler, H. Breakdown of exogenous insulin by Langerhans islets of the pancreas in vitro. Biochim. Biophys. Acta 338 (1974) 68–77.

[EC 1.8.4.2 created 1965]

1.8.7.2

Accepted name:

ferredoxin:thioredoxin reductase

Reaction:

2 reduced ferredoxin + thioredoxin disulfide + 2 H⁺ = 2 oxidized ferredoxin + thioredoxin

Systematic name:

ferredoxin:thioredoxin disulfide oxidoreductase

Comments:

The enzyme contains a [4Fe-4S] cluster and internal disulfide. It forms a mixed disulfide with thioredoxin on one side, and docks ferredoxin on the other side, enabling two one-electron transfers. The reduced thioredoxins generated by the enzyme activate the Calvin cycle enzymes EC 3.1.3.11 (fructose-bisphosphatase), EC 3.1.3.37 (sedoheptulose-bisphosphatase) and EC 2.7.1.19 (phosphoribulokinase) as well as other chloroplast enzymes by disulfide reduction.

Links to other databases:

References:

1.	Buchanan, B.B. Regulation of CO₂ assimilation in oxygenic photosynthesis: the ferredoxin/thioredoxin system. Perspective on its discovery, present status, and future development. Arch. Biochem. Biophys. 288 (1991) 1–9. [DOI] [PMID: 1910303]
2.	Chow, L.P., Iwadate, H., Yano, K., Kamo, M., Tsugita, A., Gardet-Salvi, L., Stritt-Etter, A.L. and Schurmann, P. Amino acid sequence of spinach ferredoxin:thioredoxin reductase catalytic subunit and identification of thiol groups constituting a redox-active disulfide and a [4Fe-4S] cluster. Eur. J. Biochem. 231 (1995) 149–156. [DOI] [PMID: 7628465]
3.	Staples, C.R., Ameyibor, E., Fu, W., Gardet-Salvi, L., Stritt-Etter, A.L., Schurmann, P., Knaff, D.B. and Johnson, M.K. The function and properties of the iron-sulfur center in spinach ferredoxin: thioredoxin reductase: a new biological role for iron-sulfur clusters. Biochemistry 35 (1996) 11425–11434. [DOI] [PMID: 8784198]

[EC 1.8.7.2 created 2010, modified 2023]

1.8.7.3

Accepted name:

ferredoxin:CoB-CoM heterodisulfide reductase

Reaction:

2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM = 2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H⁺

Glossary:

CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated)
CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O³-phospho-L-threonine =
O³-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine

Other name(s):

hdrABC (gene names); hdrA1B1C1 (gene names); hdrA2B2C2 (gene names)

Systematic name:

CoB,CoM:ferredoxin oxidoreductase

Comments:

HdrABC is an enzyme complex that is found in most methanogens and catalyses the reduction of the CoB-CoM heterodisulfide back to CoB and CoM. HdrA contains a FAD cofactor that acts as the entry point for electrons, which are transferred via HdrC to the HdrB catalytic subunit. One form of the enzyme from Methanosarcina acetivorans (HdrA2B2C2) can also catalyse EC 1.8.98.4, coenzyme F₄₂₀:CoB-CoM heterodisulfide,ferredoxin reductase. cf. EC 1.8.98.5, H₂:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases:

References:

1.	Buan, N.R. and Metcalf, W.W. Methanogenesis by Methanosarcina acetivorans involves two structurally and functionally distinct classes of heterodisulfide reductase. Mol. Microbiol. 75 (2010) 843–853. [DOI] [PMID: 19968794]
2.	Yan, Z., Wang, M. and Ferry, J.G. A ferredoxin- and F₄₂₀H₂-dependent, electron-bifurcating, heterodisulfide reductase with homologs in the domains Bacteria and Archaea. mBio 8 (2017) e02285-16. [DOI] [PMID: 28174314]

[EC 1.8.7.3 created 2017]

1.8.98.1

Accepted name:

dihydromethanophenazine:CoB-CoM heterodisulfide reductase

Reaction:

CoB + CoM + methanophenazine = CoM-S-S-CoB + dihydromethanophenazine

For diagram of methane biosynthesis, click here

Glossary:

CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated)
CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
methanophenazine = 2-{[(6E,10E,14E)-3,7,11,15,19-pentamethylicosa-6,10,14,18-tetraen-1-yl]oxy}phenazine
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O³-phospho-L-threonine = O³-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine

Other name(s):

hdrDE (gene names); CoB—CoM heterodisulfide reductase (ambiguous); heterodisulfide reductase (ambiguous); coenzyme B:coenzyme M:methanophenazine oxidoreductase

Systematic name:

CoB:CoM:methanophenazine oxidoreductase

Comments:

This enzyme, found in methanogenic archaea that belong to the Methanosarcinales order, regenerates CoM and CoB after the action of EC 2.8.4.1, coenzyme-B sulfoethylthiotransferase. It is a membrane-bound enzyme that contains (per heterodimeric unit) two distinct b-type hemes and two [4Fe-4S] clusters. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.5, H₂:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase and EC 1.8.98.4, coenzyme F₄₂₀:CoB-CoM heterodisulfide,ferredoxin reductase.

Links to other databases:

References:

1.	Hedderich, R., Berkessel, A. and Thauer, R.K. Purification and properties of heterodisulfide reductase from Methanobacterium thermoautotrophicum (strain Marburg). Eur. J. Biochem. 193 (1990) 255–261. [DOI] [PMID: 2121478]
2.	Abken, H.J., Tietze, M., Brodersen, J., Bäumer, S., Beifuss, U. and Deppenmeier, U. Isolation and characterization of methanophenazine and function of phenazines in membrane-bound electron transport of Methanosarcina mazei gol. J. Bacteriol. 180 (1998) 2027–2032. [PMID: 9555882]
3.	Simianu, M., Murakami, E., Brewer, J.M. and Ragsdale, S.W. Purification and properties of the heme- and iron-sulfur-containing heterodisulfide reductase from Methanosarcina thermophila. Biochemistry 37 (1998) 10027–10039. [DOI] [PMID: 9665708]
4.	Murakami, E., Deppenmeier, U. and Ragsdale, S.W. Characterization of the intramolecular electron transfer pathway from 2-hydroxyphenazine to the heterodisulfide reductase from Methanosarcina thermophila. J. Biol. Chem. 276 (2001) 2432–2439. [DOI] [PMID: 11034998]

[EC 1.8.98.1 created 2003, modified 2017]

1.8.98.4

Accepted name:

coenzyme F₄₂₀:CoB-CoM heterodisulfide,ferredoxin reductase

Reaction:

2 oxidized coenzyme F₄₂₀ + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H⁺ = 2 reduced coenzyme F₄₂₀ + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB

Glossary:

Other name(s):

hdrA2B2C2 (gene names)

Systematic name:

CoB,CoM,ferredoxin:coenzyme F₄₂₀ oxidoreductase

Comments:

The enzyme, characterized from the archaeon Methanosarcina acetivorans, catalyses the reduction of CoB-CoM heterodisulfide back to CoB and CoM. The enzyme consists of three components, HdrA, HdrB and HdrC, all of which contain [4Fe-4S] clusters. Electrons enter at HdrA, which also contains FAD, and are transferred via HdrC to the catalytic component, HdrB. During methanogenesis from acetate the enzyme catalyses the activity of EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase. However, it can also use electron bifurcation to direct electron pairs from reduced coenzyme F₄₂₀ towards the reduction of both ferredoxin and CoB-CoM heterodisulfide. This activity is proposed to take place during Fe(III)-dependent anaerobic methane oxidation. cf. EC 1.8.98.5, H₂:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases:

References:

1.	Yan, Z., Wang, M. and Ferry, J.G. A ferredoxin- and F₄₂₀H₂-dependent, electron-bifurcating, heterodisulfide reductase with homologs in the domains Bacteria and Archaea. mBio 8 (2017) e02285-16. [DOI] [PMID: 28174314]

[EC 1.8.98.4 created 2017]

1.8.98.5

Accepted name:

H₂:CoB-CoM heterodisulfide,ferredoxin reductase

Reaction:

2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H⁺ = 2 H₂ + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB

Glossary:

Systematic name:

CoB,CoM,ferredoxin:H₂ oxidoreductase

Comments:

This enzyme complex is found in H₂-oxidizing CO₂-reducing methanogenic archaea such as Methanothermobacter thermautotrophicus. It consists of a cytoplasmic complex of HdrABC reductase and MvhAGD hydrogenase. Electron pairs donated by the hydrogenase are transferred via its δ subunit to the HdrA subunit of the reductase, where they are bifurcated, reducing both ferredoxin and CoB-CoM heterodisulfide. The reductase can also form a similar complex with formate dehydrogenase, see EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.4, coenzyme F₄₂₀:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases:

References:

1.	Reeve, J.N., Beckler, G.S., Cram, D.S., Hamilton, P.T., Brown, J.W., Krzycki, J.A., Kolodziej, A.F., Alex, L., Orme-Johnson, W.H. and Walsh, C.T. A hydrogenase-linked gene in Methanobacterium thermoautotrophicum strain δ H encodes a polyferredoxin. Proc. Natl. Acad. Sci. USA 86 (1989) 3031–3035. [DOI] [PMID: 2654933]
2.	Hedderich, R., Koch, J., Linder, D. and Thauer, R.K. The heterodisulfide reductase from Methanobacterium thermoautotrophicum contains sequence motifs characteristic of pyridine-nucleotide-dependent thioredoxin reductases. Eur. J. Biochem. 225 (1994) 253–261. [DOI] [PMID: 7925445]
3.	Setzke, E., Hedderich, R., Heiden, S. and Thauer, R.K. H₂: heterodisulfide oxidoreductase complex from Methanobacterium thermoautotrophicum. Composition and properties. Eur. J. Biochem. 220 (1994) 139–148. [DOI] [PMID: 8119281]
4.	Stojanowic, A., Mander, G.J., Duin, E.C. and Hedderich, R. Physiological role of the F₄₂₀-non-reducing hydrogenase (Mvh) from Methanothermobacter marburgensis. Arch. Microbiol. 180 (2003) 194–203. [DOI] [PMID: 12856108]
5.	Kaster, A.K., Moll, J., Parey, K. and Thauer, R.K. Coupling of ferredoxin and heterodisulfide reduction via electron bifurcation in hydrogenotrophic methanogenic archaea. Proc. Natl. Acad. Sci. USA 108 (2011) 2981–2986. [DOI] [PMID: 21262829]
6.	Costa, K.C., Lie, T.J., Xia, Q. and Leigh, J.A. VhuD facilitates electron flow from H₂ or formate to heterodisulfide reductase in Methanococcus maripaludis. J. Bacteriol. 195 (2013) 5160–5165. [DOI] [PMID: 24039260]

[EC 1.8.98.5 created 2017]

1.8.98.6

Accepted name:

formate:CoB-CoM heterodisulfide,ferredoxin reductase

Reaction:

2 CO₂ + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H⁺ = 2 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB

Glossary:

Systematic name:

coenzyme B,coenzyme M,ferredoxin:formate oxidoreductase

Comments:

The enzyme is found in formate-oxidizing CO₂-reducing methanogenic archaea such as Methanococcus maripaludis. It consists of a cytoplasmic complex of HdrABC reductase and formate dehydrogenase. Electron pairs donated by formate dehydrogenase are transferred to the HdrA subunit of the reductase, where they are bifurcated, reducing both ferredoxin and CoB-CoM heterodisulfide. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.4, coenzyme F₄₂₀:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.5, H₂:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases:

References:

1.	Costa, K.C., Wong, P.M., Wang, T., Lie, T.J., Dodsworth, J.A., Swanson, I., Burn, J.A., Hackett, M. and Leigh, J.A. Protein complexing in a methanogen suggests electron bifurcation and electron delivery from formate to heterodisulfide reductase. Proc. Natl. Acad. Sci. USA 107 (2010) 11050–11055. [DOI] [PMID: 20534465]
2.	Costa, K.C., Lie, T.J., Xia, Q. and Leigh, J.A. VhuD facilitates electron flow from H₂ or formate to heterodisulfide reductase in Methanococcus maripaludis. J. Bacteriol. 195 (2013) 5160–5165. [DOI] [PMID: 24039260]

[EC 1.8.98.6 created 2017]

1.10.3.10

Transferred entry:

ubiquinol oxidase (H⁺-transporting). Now EC 7.1.1.3, ubiquinol oxidase (H⁺-transporting)

[EC 1.10.3.10 created 2011, modified 2014, deleted 2018]

1.11.1.20

Accepted name:

prostamide/prostaglandin F_2α synthase

Reaction:

thioredoxin + (5Z,9α,11α,13E,15S)-9,11-epidioxy-15-hydroxy-prosta-5,13-dienoate = thioredoxin disulfide + (5Z,9α,11α,13E,15S)-9,11,15-trihydroxyprosta-5,13-dienoate

Glossary:

prostamide H₂ = (5Z)-N-(2-hydroxyethyl)-7-{(1R,4S,5R,6R)-6-[(1E,3S)-3-hydroxyoct-1-en-1-yl]-2,3-dioxabicyclo[2.2.1]hept-5-yl}hept-5-enamide
prostamide F_2α = (5Z,9α,11α,13E,15S)-9,11,15-trihydroxy-N-(2-hydroxyethyl)prosta-5,13-dien-1-amide
prostaglandin H₂ = (5Z,9α,11α,13E,15S)-9,11-epidioxy-15-hydroxy-prosta-5,13-dienoate
prostaglandin F_2α = (5Z,9α,11α,13E,15S)-9,11,15-trihydroxyprosta-5,13-dienoate

Other name(s):

prostamide/PGF synthase; prostamide F synthase; prostamide/prostaglandin F synthase; tPGF synthase

Systematic name:

thioredoxin:(5Z,9α,11α,13E,15S)-9,11-epidioxy-15-hydroxy-prosta-5,13-dienoate oxidoreductase

Comments:

The enzyme contains a thioredoxin-type disulfide as a catalytic group. Prostamide H₂ and prostaglandin H₂ are the best substrates; the latter is converted to prostaglandin F_2α. The enzyme also reduces tert-butyl hydroperoxide, cumene hydroperoxide and H₂O₂, but not prostaglandin D₂ or prostaglandin E₂.

Links to other databases:

References:

1.	Moriuchi, H., Koda, N., Okuda-Ashitaka, E., Daiyasu, H., Ogasawara, K., Toh, H., Ito, S., Woodward, D.F. and Watanabe, K. Molecular characterization of a novel type of prostamide/prostaglandin F synthase, belonging to the thioredoxin-like superfamily. J. Biol. Chem. 283 (2008) 792–801. [DOI] [PMID: 18006499]
2.	Yoshikawa, K., Takei, S., Hasegawa-Ishii, S., Chiba, Y., Furukawa, A., Kawamura, N., Hosokawa, M., Woodward, D.F., Watanabe, K. and Shimada, A. Preferential localization of prostamide/prostaglandin F synthase in myelin sheaths of the central nervous system. Brain Res. 1367 (2011) 22–32. [DOI] [PMID: 20950588]

[EC 1.11.1.20 created 2011]

1.12.99.2

Deleted entry:

coenzyme-M-7-mercaptoheptanoylthreonine-phosphate-heterodisulfide hydrogenase. Now shown to be two enzymes, EC 1.12.98.3, Methanosarcina-phenazine hydrogenase and EC 1.8.98.1, CoB—CoM heterodisulfide reductase

[EC 1.12.99.2 created 1992, deleted 2002]

1.13.11.50

Accepted name:

acetylacetone-cleaving enzyme

Reaction:

pentane-2,4-dione + O₂ = acetate + 2-oxopropanal

Glossary:

2-oxopropanal = methylglyoxal

Other name(s):

Dke1; acetylacetone dioxygenase; diketone cleaving dioxygenase; diketone cleaving enzyme

Systematic name:

acetylacetone:oxygen oxidoreductase

Comments:

An iron(II)-dependent enzyme. Forms the first step in the acetylacetone degradation pathway of Acinetobacter johnsonii. While acetylacetone is by far the best substrate, heptane-3,5-dione, octane-2,4-dione, 2-acetylcyclohexanone and ethyl acetoacetate can also act as substrates.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 524047-53-8

References:

1.	Straganz, G.D., Glieder, A., Brecker, L., Ribbons, D.W. and Steiner, W. Acetylacetone-cleaving enzyme Dke1: a novel C-C-bond-cleaving enzyme from Acinetobacter johnsonii. Biochem. J. 369 (2003) 573–581. [DOI] [PMID: 12379146]

[EC 1.13.11.50 created 2003]

1.13.11.64

Accepted name:

5-nitrosalicylate dioxygenase

Reaction:

5-nitrosalicylate + O₂ = 2-oxo-3-(5-oxofuran-2-ylidene)propanoate + nitrite (overall reaction)
(1a) 5-nitrosalicylate + O₂ = 4-nitro-6-oxohepta-2,4-dienedioate
(1b) 4-nitro-6-oxohepta-2,4-dienedioate = 2-oxo-3-(5-oxofuran-2-ylidene)propanoate + nitrite (spontaneous)

Other name(s):

naaB (gene name); 5-nitrosalicylate:oxygen 1,2-oxidoreductase (decyclizing)

Systematic name:

5-nitrosalicylate:oxygen 1,2-oxidoreductase (ring-opening)

Comments:

The enzyme, characterized from the soil bacterium Bradyrhizobium sp. JS329, is involved in the pathway of 5-nitroanthranilate degradation. It is unusual in being able to catalyse the ring fission without the requirement for prior removal of the nitro group. The product undergoes spontaneous lactonization, with concurrent elimination of the nitro group.

Links to other databases:

References:

1.	Qu, Y. and Spain, J.C. Biodegradation of 5-nitroanthranilic acid by Bradyrhizobium sp. strain JS329. Appl. Environ. Microbiol. 76 (2010) 1417–1422. [DOI] [PMID: 20081004]
2.	Qu, Y. and Spain, J.C. Molecular and biochemical characterization of the 5-nitroanthranilic acid degradation pathway in Bradyrhizobium sp. strain JS329. J. Bacteriol. 193 (2011) 3057–3063. [DOI] [PMID: 21498645]

[EC 1.13.11.64 created 2012]

1.13.11.67

Accepted name:

8′-apo-β-carotenoid 14′,13′-cleaving dioxygenase

Reaction:

8′-apo-β-carotenol + O₂ = 14′-apo-β-carotenal + an uncharacterized product

For diagram of 8′-apo-β-carotenal metabolites, click here

Other name(s):

8′-apo-β-carotenol:O₂ oxidoreductase (14′,13′-cleaving)

Systematic name:

8′-apo-β-carotenol:oxygen oxidoreductase (14′,13′-cleaving)

Comments:

A thiol-dependent enzyme isolated from rat and rabbit. Unlike EC 1.13.11.63, β-carotene-15,15′-dioxygenase, it is not active towards β-carotene. The secondary product has not been characterized, but may be (3E,5E)-7-hydroxy-6-methylhepta-3,5-dien-2-one.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 198028-39-6

References:

1.	Dmitrovskii, A.A., Gessler, N.N., Gomboeva, S.B., Ershov, Yu.V. and Bykhovsky, V.Ya. Enzymatic oxidation of β-apo-8′-carotenol to β-apo-14′-carotenal by an enzyme different from β-carotene-15,15′-dioxygenase. Biochemistry (Mosc.) 62 (1997) 787–792. [PMID: 9331970]

[EC 1.13.11.67 created 2000 as EC 1.13.12.12, transferred 2012 to EC 1.13.11.67]

1.13.11.69

Accepted name:

carlactone synthase

Reaction:

9-cis-10′-apo-β-carotenal + 2 O₂ = carlactone + (2E,4E,6E)-7-hydroxy-4-methylhepta-2,4,6-trienal

For diagram of strigol biosynthesis, click here

Glossary:

carlactone = 3-methyl-5-{[(1Z,3E)-2-methyl-4-(2,6,6-trimethylcyclohex-1-en-1-yl)buta-1,3-dien-1-yl]oxy}-5H-furan-2-one

Other name(s):

CCD8 (gene name); MAX4 (gene name); NCED8 (gene name)

Systematic name:

9-cis-10′-apo-β-carotenal:oxygen oxidoreductase (14,15-cleaving, carlactone-forming)

Comments:

Requires Fe²⁺. The enzyme participates in a pathway leading to biosynthesis of strigolactones, plant hormones involved in promotion of symbiotic associations known as arbuscular mycorrhiza. Also catalyses EC 1.13.11.70, all-trans-10′-apo-β-carotenal 13,14-cleaving dioxygenase, but 10-fold slower.

Links to other databases:

References:

1.	Sorefan, K., Booker, J., Haurogne, K., Goussot, M., Bainbridge, K., Foo, E., Chatfield, S., Ward, S., Beveridge, C., Rameau, C. and Leyser, O. MAX4 and RMS1 are orthologous dioxygenase-like genes that regulate shoot branching in Arabidopsis and pea. Genes Dev. 17 (2003) 1469–1474. [DOI] [PMID: 12815068]
2.	Schwartz, S.H., Qin, X. and Loewen, M.C. The biochemical characterization of two carotenoid cleavage enzymes from Arabidopsis indicates that a carotenoid-derived compound inhibits lateral branching. J. Biol. Chem. 279 (2004) 46940–46945. [DOI] [PMID: 15342640]
3.	Alder, A., Jamil, M., Marzorati, M., Bruno, M., Vermathen, M., Bigler, P., Ghisla, S., Bouwmeester, H., Beyer, P. and Al-Babili, S. The path from β-carotene to carlactone, a strigolactone-like plant hormone. Science 335 (2012) 1348–1351. [DOI] [PMID: 22422982]

[EC 1.13.11.69 created 2012]

1.13.11.72

Accepted name:

2-hydroxyethylphosphonate dioxygenase

Reaction:

2-hydroxyethylphosphonate + O₂ = hydroxymethylphosphonate + formate

For diagram of phosphonate metabolism, click here

Other name(s):

HEPD; phpD (gene name); 2-hydroxyethylphosphonate:O₂ 1,2-oxidoreductase (hydroxymethylphosphonate forming)

Systematic name:

2-hydroxyethylphosphonate:oxygen 1,2-oxidoreductase (hydroxymethylphosphonate-forming)

Comments:

Requires non-heme-iron(II). Isolated from some bacteria including Streptomyces hygroscopicus and Streptomyces viridochromogenes. The pro-R hydrogen at C-2 of the ethyl group is retained by the formate ion. Any stereochemistry at C-1 of the ethyl group is lost. One atom from dioxygen is present in each product. Involved in phosphinothricin biosynthesis.

Links to other databases:

References:

1.	Cicchillo, R.M., Zhang, H., Blodgett, J.A., Whitteck, J.T., Li, G., Nair, S.K., van der Donk, W.A. and Metcalf, W.W. An unusual carbon-carbon bond cleavage reaction during phosphinothricin biosynthesis. Nature 459 (2009) 871–874. [DOI] [PMID: 19516340]
2.	Whitteck, J.T., Malova, P., Peck, S.C., Cicchillo, R.M., Hammerschmidt, F. and van der Donk, W.A. On the stereochemistry of 2-hydroxyethylphosphonate dioxygenase. J. Am. Chem. Soc. 133 (2011) 4236–4239. [DOI] [PMID: 21381767]
3.	Peck, S.C., Cooke, H.A., Cicchillo, R.M., Malova, P., Hammerschmidt, F., Nair, S.K. and van der Donk, W.A. Mechanism and substrate recognition of 2-hydroxyethylphosphonate dioxygenase. Biochemistry 50 (2011) 6598–6605. [DOI] [PMID: 21711001]

[EC 1.13.11.72 created 2012]

1.13.11.86

Accepted name:

5-aminosalicylate 1,2-dioxygenase

Reaction:

5-aminosalicylate + O₂ = (2Z,4E)-4-amino-6-oxohepta-2,4-dienedioate

Glossary:

5-aminosalicylate = 5-amino-2-hydroxybenzoate

Other name(s):

mabB (gene name)

Systematic name:

5-aminosalicylate:oxygen 1,2-oxidoreductase (ring-opening)

Comments:

Requires iron(II). The enzyme, characterized from different bacteria, is a nonheme iron dioxygenase in the bicupin family.

Links to other databases:

References:

1.	Stolz, A., Nortemann, B. and Knackmuss, H.J. Bacterial metabolism of 5-aminosalicylic acid. Initial ring cleavage. Biochem. J. 282 (1992) 675–680. [PMID: 1554350]
2.	Yu, H., Zhao, S. and Guo, L. Novel gene encoding 5-aminosalicylate 1,2-dioxygenase from Comamonas sp. strain QT12 and catalytic properties of the purified enzyme. J. Bacteriol. 200 (2018) . [PMID: 29038259]

[EC 1.13.11.86 created 2018]

1.13.12.11

Deleted entry:

methylphenyltetrahydropyridine N-monooxygenase. The activity is due to EC 1.14.13.8, flavin-containing monooxygenase

[EC 1.13.12.11 created 1992, deleted 2006]

1.13.12.12

Transferred entry:

apo-β-carotenoid-14′,13′-dioxygenase. The enzyme was misclassified and has been transferred to EC 1.13.11.67, 8-apo-β-carotenoid 14′,13′-cleaving dioxygenase

[EC 1.13.12.12 created 2000, modified 2001, deleted 2012]

1.14.13.8

Accepted name:

flavin-containing monooxygenase

Reaction:

N,N-dimethylaniline + NADPH + H⁺ + O₂ = N,N-dimethylaniline N-oxide + NADP⁺ + H₂O

Other name(s):

dimethylaniline oxidase; dimethylaniline N-oxidase; FAD-containing monooxygenase; N,N-dimethylaniline monooxygenase; DMA oxidase; flavin mixed function oxidase; Ziegler’s enzyme; mixed-function amine oxidase; FMO; FMO-I; FMO-II; FMO1; FMO2; FMO3; FMO4; FMO5; flavin monooxygenase; methylphenyltetrahydropyridine N-monooxygenase; 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine:oxygen N-oxidoreductase; dimethylaniline monooxygenase (N-oxide-forming)

Systematic name:

N,N-dimethylaniline,NADPH:oxygen oxidoreductase (N-oxide-forming)

Comments:

A flavoprotein. A broad spectrum monooxygenase that accepts substrates as diverse as hydrazines, phosphines, boron-containing compounds, sulfides, selenides, iodide, as well as primary, secondary and tertiary amines [3,4]. This enzyme is distinct from other monooxygenases in that the enzyme forms a relatively stable hydroperoxy flavin intermediate [4,5]. This microsomal enzyme generally converts nucleophilic heteroatom-containing chemicals and drugs into harmless, readily excreted metabolites. For example, N-oxygenation is largely responsible for the detoxification of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) [2,6]

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37256-73-8

References:

1.	Ziegler, D.M. and Pettit, F.H. Microsomal oxidases. I. The isolation and dialkylarylamine oxygenase activity of pork liver microsomes. Biochemistry 5 (1966) 2932–2938. [PMID: 4381353]
2.	Chiba, K., Kubota, E., Miyakawa, T., Kato, Y. and Ishizaki, T. Characterization of hepatic microsomal metabolism as an in vivo detoxication pathway of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice. J. Pharmacol. Exp. Ther. 246 (1988) 1108–1115. [PMID: 3262153]
3.	Cashman, J.R. Structural and catalytic properties of the mammalian flavin-containing monooxygenase. Chem. Res. Toxicol. 8 (1995) 165–181.
4.	Cashman, J.R. and Zhang, J. Human flavin-containing monooxygenases. Annu. Rev. Pharmacol. Toxicol. 46 (2006) 65–100. [DOI] [PMID: 16402899]
5.	Jones, K.C. and Ballou, D.P. Reactions of the 4a-hydroperoxide of liver microsomal flavin-containing monooxygenase with nucleophilic and electrophilic substrates. J. Biol. Chem. 261 (1986) 2553–2559. [PMID: 3949735]
6.	Chiba, K., Kobayashi, K., Itoh, K., Itoh, S., Chiba, T., Ishizaki, T. and Kamataki, T. N-Oxygenation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine by the rat liver flavin-containing monooxygenase expressed in yeast cells. Eur. J. Pharmacol. 293 (1995) 97–100. [PMID: 7672012]

[EC 1.14.13.8 created 1972 (EC 1.13.12.11 created 1992, part-incorporated 2006), modified 2006]

1.14.13.30

Transferred entry:

leukotriene-B₄ 20-monooxygenase. Now EC 1.14.14.94, leukotriene-B₄ 20-monooxygenase

[EC 1.14.13.30 created 1989, deleted 2018]

1.14.13.96

Transferred entry:

5β-cholestane-3α,7α-diol 12α-hydroxylase. Now EC 1.14.14.139, 5β-cholestane-3α,7α-diol 12α-hydroxylase

[EC 1.14.13.96 created 2005, deleted 2018]

1.14.13.105

Accepted name:

monocyclic monoterpene ketone monooxygenase

Reaction:

(1) (–)-menthone + NADPH + H⁺ + O₂ = (4R,7S)-7-isopropyl-4-methyloxepan-2-one + NADP⁺ + H₂O
(2) dihydrocarvone + NADPH + H⁺ + O₂ = 4-isopropenyl-7-methyloxepan-2-one + NADP⁺ + H₂O
(3) (iso)-dihydrocarvone + NADPH + H⁺ + O₂ = 6-isopropenyl-3-methyloxepan-2-one + NADP⁺ + H₂O
(4a) 1-hydroxymenth-8-en-2-one + NADPH + H⁺ + O₂ = 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one + NADP⁺ + H₂O
(4b) 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one = 3-isopropenyl-6-oxoheptanoate (spontaneous)

For diagram of (–)-carvone catabolism, click here, for diagram of limonene catabolism, click here and for diagram of menthol biosynthesis, click here

Other name(s):

1-hydroxy-2-oxolimonene 1,2-monooxygenase; dihydrocarvone 1,2-monooxygenase; MMKMO

Systematic name:

(–)-menthone,NADPH:oxygen oxidoreductase

Comments:

A flavoprotein (FAD). This Baeyer-Villiger monooxygenase enzyme from the Gram-positive bacterium Rhodococcus erythropolis DCL14 has wide substrate specificity, catalysing the lactonization of a large number of monocyclic monoterpene ketones and substituted cyclohexanones [2]. Both (1R,4S)- and (1S,4R)-1-hydroxymenth-8-en-2-one are metabolized, with the lactone product spontaneously rearranging to form 3-isopropenyl-6-oxoheptanoate [1].

Links to other databases:

References:

1.	van der Werf, M.J., Swarts, H.J. and de Bont, J.A. Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene. Appl. Environ. Microbiol. 65 (1999) 2092–2102. [PMID: 10224006]
2.	Van Der Werf, M.J. Purification and characterization of a Baeyer-Villiger mono-oxygenase from Rhodococcus erythropolis DCL14 involved in three different monocyclic monoterpene degradation pathways. Biochem. J. 347 (2000) 693–701. [PMID: 10769172]
3.	van der Werf, M.J. and Boot, A.M. Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14. Microbiology 146 (2000) 1129–1141. [DOI] [PMID: 10832640]

[EC 1.14.13.105 created 2008]

1.14.13.107

Accepted name:

limonene 1,2-monooxygenase

Reaction:

(1) (S)-limonene + NAD(P)H + H⁺ + O₂ = 1,2-epoxymenth-8-ene + NAD(P)⁺ + H₂O
(2) (R)-limonene + NAD(P)H + H⁺ + O₂ = 1,2-epoxymenth-8-ene + NAD(P)⁺ + H₂O

For diagram of limonene catabolism, click here

Glossary:

limonene = a monoterpenoid
(S)-limonene = (-)-limonene
(R)-limonene = (+)-limonene
limonene-1,2-epoxide = 1,2-epoxymenth-8-ene = 1-methyl-4-(prop-1-en-2-yl)-7-oxabicyclo[4.1.0]heptane

Systematic name:

limonene,NAD(P)H:oxygen oxidoreductase

Comments:

A flavoprotein (FAD). Limonene is the most widespread terpene and is formed by more than 300 plants. Rhodococcus erythropolis DCL14, a Gram-positive bacterium, is able to grow on both (S)-limonene and (R)-limonene as the sole source of carbon and energy. NADPH can act instead of NADH, although more slowly. It has not been established if the product formed is optically pure or a mixture of two enantiomers.

Links to other databases:

References:

1.	van der Werf, M.J., Swarts, H.J. and de Bont, J.A. Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene. Appl. Environ. Microbiol. 65 (1999) 2092–2102. [PMID: 10224006]

[EC 1.14.13.107 created 2009]

1.14.13.148

Accepted name:

trimethylamine monooxygenase

Reaction:

N,N,N-trimethylamine + NADPH + H⁺ + O₂ = N,N,N-trimethylamine N-oxide + NADP⁺ + H₂O

Other name(s):

flavin-containing monooxygenase 3; FMO3; tmm (gene name)

Systematic name:

N,N,N-trimethylamine,NADPH:oxygen oxidoreductase (N-oxide-forming)

Comments:

A flavoprotein. The bacterial enzyme enables bacteria to use trimethylamine as the sole source of carbon and energy [1,4]. The mammalian enzyme is involved in detoxification of trimethylamine. Mutations in the human enzyme cause the inheritable disease known as trimethylaminuria (fish odor syndrome) [2,3].

Links to other databases:

References:

1.	Large, P.J., Boulton, C.A. and Crabbe, M.J. The reduced nicotinamide-adenine dinucleotide phosphate- and oxygen-dependent N-oxygenation of trimethylamine by Pseudomonas aminovorans. Biochem. J. 128 (1972) 137P–138P. [PMID: 4404764]
2.	Dolphin, C.T., Riley, J.H., Smith, R.L., Shephard, E.A. and Phillips, I.R. Structural organization of the human flavin-containing monooxygenase 3 gene (FMO3), the favored candidate for fish-odor syndrome, determined directly from genomic DNA. Genomics 46 (1997) 260–267. [DOI] [PMID: 9417913]
3.	Treacy, E.P., Akerman, B.R., Chow, L.M., Youil, R., Bibeau, C., Lin, J., Bruce, A.G., Knight, M., Danks, D.M., Cashman, J.R. and Forrest, S.M. Mutations of the flavin-containing monooxygenase gene (FMO3) cause trimethylaminuria, a defect in detoxication. Hum. Mol. Genet. 7 (1998) 839–845. [DOI] [PMID: 9536088]
4.	Chen, Y., Patel, N.A., Crombie, A., Scrivens, J.H. and Murrell, J.C. Bacterial flavin-containing monooxygenase is trimethylamine monooxygenase. Proc. Natl. Acad. Sci. USA 108 (2011) 17791–17796. [DOI] [PMID: 22006322]

[EC 1.14.13.148 created 2012]

1.14.13.149

Accepted name:

phenylacetyl-CoA 1,2-epoxidase

Reaction:

phenylacetyl-CoA + NADPH + H⁺ + O₂ = 2-(1,2-epoxy-1,2-dihydrophenyl)acetyl-CoA + NADP⁺ + H₂O

For diagram of aerobic phenylacetate catabolism, click here

Glossary:

2-(1,2-epoxy-1,2-dihydrophenyl)acetyl-CoA = 2-{7-oxabicyclo[4.1.0]hepta-2,4-dien-1-yl}acetyl-CoA

Other name(s):

ring 1,2-phenylacetyl-CoA epoxidase; phenylacetyl-CoA monooxygenase; PaaAC; PaaABC(D)E

Systematic name:

phenylacetyl-CoA:oxygen oxidoreductase (1,2-epoxidizing)

Comments:

Part of the aerobic pathway of phenylacetate catabolism in Escherichia coli and Pseudomonas putida.

Links to other databases:

References:

1.	Teufel, R., Mascaraque, V., Ismail, W., Voss, M., Perera, J., Eisenreich, W., Haehnel, W. and Fuchs, G. Bacterial phenylalanine and phenylacetate catabolic pathway revealed. Proc. Natl. Acad. Sci. USA 107 (2010) 14390–14395. [DOI] [PMID: 20660314]
2.	Grishin, A.M., Ajamian, E., Zhang, L. and Cygler, M. Crystallization and preliminary X-ray analysis of PaaAC, the main component of the hydroxylase of the Escherichia coli phenylacetyl-coenzyme A oxygenase complex. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 66 (2010) 1045–1049. [DOI] [PMID: 20823522]
3.	Grishin, A.M., Ajamian, E., Tao, L., Zhang, L., Menard, R. and Cygler, M. Structural and functional studies of the Escherichia coli phenylacetyl-CoA monooxygenase complex. J. Biol. Chem. 286 (2011) 10735–10743. [DOI] [PMID: 21247899]

[EC 1.14.13.149 created 2012]

1.14.13.182

Accepted name:

2-heptyl-3-hydroxy-4(1H)-quinolone synthase

Reaction:

2-heptyl-4(1H)-quinolone + NADH + H⁺ + O₂ = 2-heptyl-3-hydroxy-4(1H)-quinolone + NAD⁺ + H₂O

Glossary:

2-heptyl-4(1H)-quinolone = 2-heptyl-4-hydroxyquinoline
2-heptyl-3-hydroxy-4(1H)-quinolone = 2-heptyl-3,4-dihydroxyquinoline

Other name(s):

PqsH; 2-heptyl-3,4-dihydroxyquinoline synthase

Systematic name:

2-heptyl-4(1H)-quinolone,NADH:oxygen oxidoreductase (3-hydroxylating)

Comments:

The enzyme from the bacterium Pseudomonas aeruginosa catalyses the terminal step in biosynthesis of the signal molecule 2-heptyl-3,4-dihydroxyquinoline that plays a role in regulation of virulence genes.

Links to other databases:

References:

1.	Schertzer, J.W., Brown, S.A. and Whiteley, M. Oxygen levels rapidly modulate Pseudomonas aeruginosa social behaviours via substrate limitation of PqsH. Mol. Microbiol. 77 (2010) 1527–1538. [DOI] [PMID: 20662781]

[EC 1.14.13.182 created 2013]

1.14.13.194

Transferred entry:

phylloquinone ω-hydroxylase. Now EC 1.14.14.78, phylloquinone ω-hydroxylase

[EC 1.14.13.194 created 2014, deleted 2018]

1.14.13.197

Transferred entry:

dihydromonacolin L hydroxylase. Now EC 1.14.14.124, dihydromonacolin L hydroxylase

[EC 1.14.13.197 created 2014, deleted 2018]

1.14.13.198

Transferred entry:

monacolin L hydroxylase. Now EC 1.14.14.125, monacolin L hydroxylase

[EC 1.14.13.198 created 2014, deleted 2018]

1.14.13.211

Accepted name:

rifampicin monooxygenase

Reaction:

rifampicin + NAD(P)H + O₂ = 2-hydroxy-2,27-secorifampicin + NAD(P)⁺ + H₂O

For diagram of rifampicin, click here

Glossary:

rifampicin = (2S,12Z,14E,16S,17S,18R,19R,20R,21S,22R,23S,24E)-5,6,9,17,19-pentahydroxy-23-methoxy-2,4,12,16,18,20,22-heptamethyl-8-{[(E)-(4-methylpiperazin-1-yl)imino]methyl}-1,11-dioxo-1,2-dihydro-2,7-(epoxypentadeca-1,11,13-trienoimino)nathpho[2,1-b]furan-21-yl acetate

Other name(s):

RIF-O; ROX; RIFMO; rifampicin:NAD(P)H:oxygen oxidoreductase (2′-N-hydroxyrifampicin-forming) (incorrect)

Systematic name:

rifampicin:NAD(P)H:oxygen oxidoreductase (2-hydroxy-2,27-secorifampicin-forming; ring-cleaving)

Comments:

The enzyme has been found in a variety of environmental bacteria, notably Rhodococcus, Nocardia, and Streptomyces. It hydroxylates C-2 of rifampicin leading to its macro-ring cleaving.

Links to other databases: