EC |
1.14.11.55 |
Accepted name: |
ectoine hydroxylase |
Reaction: |
ectoine + 2-oxoglutarate + O2 = 5-hydroxyectoine + succinate + CO2 |
Glossary: |
ectoine = (4S)-2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylate
5-hydroxyectoine = (4S,5S)-5-hydroxy-2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylate
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Other name(s): |
ectD (gene name); ectoine dioxygenase |
Systematic name: |
ectoine,2-oxoglutarate:oxygen oxidoreductase (5-hydroxylating) |
Comments: |
Requires Fe2+ and ascorbate. The enzyme, found in bacteria, is specific for ectoine. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Bursy, J., Pierik, A.J., Pica, N. and Bremer, E. Osmotically induced synthesis of the compatible solute hydroxyectoine is mediated by an evolutionarily conserved ectoine hydroxylase. J. Biol. Chem. 282 (2007) 31147–31155. [DOI] [PMID: 17636255] |
2. |
Bursy, J., Kuhlmann, A.U., Pittelkow, M., Hartmann, H., Jebbar, M., Pierik, A.J. and Bremer, E. Synthesis and uptake of the compatible solutes ectoine and 5-hydroxyectoine by Streptomyces coelicolor A3(2) in response to salt and heat stresses. Appl. Environ. Microbiol. 74 (2008) 7286–7296. [DOI] [PMID: 18849444] |
3. |
Reuter, K., Pittelkow, M., Bursy, J., Heine, A., Craan, T. and Bremer, E. Synthesis of 5-hydroxyectoine from ectoine: crystal structure of the non-heme iron(II) and 2-oxoglutarate-dependent dioxygenase EctD. PLoS One 5 (2010) e10647. [DOI] [PMID: 20498719] |
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[EC 1.14.11.55 created 2017] |
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EC |
2.3.1.178 |
Accepted name: |
diaminobutyrate acetyltransferase |
Reaction: |
acetyl-CoA + L-2,4-diaminobutanoate = CoA + (2S)-4-acetamido-2-aminobutanoate |
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For diagram of ectoine biosynthesis, click here |
Other name(s): |
L-2,4-diaminobutyrate acetyltransferase; L-2,4-diaminobutanoate acetyltransferase; EctA; diaminobutyric acid acetyltransferase; DABA acetyltransferase; 2,4-diaminobutanoate acetyltransferase; DAB acetyltransferase; DABAcT; acetyl-CoA:L-2,4-diaminobutanoate 4-N-acetyltransferase |
Systematic name: |
acetyl-CoA:L-2,4-diaminobutanoate N4-acetyltransferase |
Comments: |
Requires Na+ or K+ for maximal activity [3]. Ornithine, lysine, aspartate, and α-, β- and γ-aminobutanoate cannot act as substrates [3]. However, acetyl-CoA can be replaced by propanoyl-CoA, although the reaction proceeds more slowly [3]. Forms part of the ectoine-biosynthesis pathway. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 130456-92-7 |
References: |
1. |
Peters, P., Galinski, E.A. and Truper, H.G. The biosynthesis of ectoine. FEMS Microbiol. Lett. 71 (1990) 157–162. |
2. |
Ono, H., Sawada, K., Khunajakr, N., Tao, T., Yamamoto, M., Hiramoto, M., Shinmyo, A., Takano, M. and Murooka, Y. Characterization of biosynthetic enzymes for ectoine as a compatible
solute in a moderately halophilic eubacterium, Halomonas elongata. J. Bacteriol. 181 (1999) 91–99. [PMID: 9864317] |
3. |
Reshetnikov, A.S., Mustakhimov, I.I., Khmelenina, V.N. and Trotsenko, Y.A. Cloning, purification, and characterization of diaminobutyrate acetyltransferase from the halotolerant methanotroph Methylomicrobium alcaliphilum 20Z. Biochemistry (Mosc.) 70 (2005) 878–883. [PMID: 16212543] |
4. |
Kuhlmann, A.U. and Bremer, E. Osmotically regulated synthesis of the compatible solute ectoine in
Bacillus pasteurii and related Bacillus spp. Appl. Environ. Microbiol. 68 (2002) 772–783. [DOI] [PMID: 11823218] |
5. |
Louis, P. and Galinski, E.A. Characterization of genes for the biosynthesis of the compatible solute ectoine from Marinococcus halophilus and osmoregulated expression in Escherichia coli. Microbiology 143 (1997) 1141–1149. [DOI] [PMID: 9141677] |
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[EC 2.3.1.178 created 2006] |
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EC |
2.6.1.76 |
Accepted name: |
diaminobutyrate—2-oxoglutarate transaminase |
Reaction: |
L-2,4-diaminobutanoate + 2-oxoglutarate = L-aspartate 4-semialdehyde + L-glutamate |
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For diagram of ectoine biosynthesis, click here |
Other name(s): |
L-2,4-diaminobutyrate:2-ketoglutarate 4-aminotransferase; 2,4-diaminobutyrate 4-aminotransferase; diaminobutyrate aminotransferase; DABA aminotransferase; DAB aminotransferase; EctB; diaminibutyric acid aminotransferase; L-2,4-diaminobutyrate:2-oxoglutarate 4-aminotransferase |
Systematic name: |
L-2,4-diaminobutanoate:2-oxoglutarate 4-aminotransferase |
Comments: |
A pyridoxal-phosphate protein that requires potassium for activity [4]. In the proteobacterium Acinetobacter baumannii, this enzyme is cotranscribed with the neighbouring ddc gene that also encodes EC 4.1.1.86, diaminobutyrate decarboxylase. Differs from EC 2.6.1.46, diaminobutyrate—pyruvate transaminase, which has pyruvate as the amino-group acceptor. This is the first enzyme in the ectoine-biosynthesis pathway, the other enzymes involved being EC 2.3.1.178, diaminobutyrate acetyltransferase and EC 4.2.1.108, ectoine synthase [3,4]. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 196622-96-5 |
References: |
1. |
Ikai, H. and Yamamoto, S. Identification and analysis of a gene encoding L-2,4-diaminobutyrate:2-ketoglutarate 4-aminotransferase involved in the 1,3-diaminopropane production pathway in Acinetobacter baumannii. J. Bacteriol. 179 (1997) 5118–5125. [DOI] [PMID: 9260954] |
2. |
Ikai, H. and Yamamoto, S. Two genes involved in the 1,3-diaminopropane production pathway in Haemophilus influenzae. Biol. Pharm. Bull. 21 (1998) 170–173. [PMID: 9514614] |
3. |
Peters, P., Galinski, E.A. and Truper, H.G. The biosynthesis of ectoine. FEMS Microbiol. Lett. 71 (1990) 157–162. |
4. |
Ono, H., Sawada, K., Khunajakr, N., Tao, T., Yamamoto, M., Hiramoto, M., Shinmyo, A., Takano, M. and Murooka, Y. Characterization of biosynthetic enzymes for ectoine as a compatible
solute in a moderately halophilic eubacterium, Halomonas elongata. J. Bacteriol. 181 (1999) 91–99. [PMID: 9864317] |
5. |
Kuhlmann, A.U. and Bremer, E. Osmotically regulated synthesis of the compatible solute ectoine in
Bacillus pasteurii and related Bacillus spp. Appl. Environ. Microbiol. 68 (2002) 772–783. [DOI] [PMID: 11823218] |
6. |
Louis, P. and Galinski, E.A. Characterization of genes for the biosynthesis of the compatible solute ectoine from Marinococcus halophilus and osmoregulated expression in Escherichia coli. Microbiology 143 (1997) 1141–1149. [DOI] [PMID: 9141677] |
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[EC 2.6.1.76 created 2000, modified 2006] |
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EC |
3.5.1.125 |
Accepted name: |
N2-acetyl-L-2,4-diaminobutanoate deacetylase |
Reaction: |
(2S)-2-acetamido-4-aminobutanoate + H2O = L-2,4-diaminobutanoate + acetate |
Other name(s): |
doeB (gene name) |
Systematic name: |
(2S)-2-acetamido-4-aminobutanoate amidohydrolase |
Comments: |
The enzyme, found in bacteria, has no activity with (2S)-4-acetamido-2-aminobutanoate (cf. EC 3.5.4.44, ectoine hydrolase). |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Schwibbert, K., Marin-Sanguino, A., Bagyan, I., Heidrich, G., Lentzen, G., Seitz, H., Rampp, M., Schuster, S.C., Klenk, H.P., Pfeiffer, F., Oesterhelt, D. and Kunte, H.J. A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581 T. Environ. Microbiol. 13 (2011) 1973–1994. [DOI] [PMID: 20849449] |
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[EC 3.5.1.125 created 2017] |
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EC |
3.5.4.44 |
Accepted name: |
ectoine hydrolase |
Reaction: |
ectoine + H2O = (2S)-2-acetamido-4-aminobutanoate |
Glossary: |
ectoine = (4S)-2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylate |
Other name(s): |
doeA (gene name) |
Systematic name: |
ectoine aminohydrolase |
Comments: |
The enzyme, found in some halophilic bacteria, is involved in the degradation of the compatible solute ectoine. The enzyme, which belongs to peptidase family M24, only acts in the direction of ectoine hydrolysis. It also produces smaller amounts of (2S)-4-acetamido-2-aminobutanoate, which is recycled back to ectoine by EC 4.2.1.108, ectoine synthase. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Schwibbert, K., Marin-Sanguino, A., Bagyan, I., Heidrich, G., Lentzen, G., Seitz, H., Rampp, M., Schuster, S.C., Klenk, H.P., Pfeiffer, F., Oesterhelt, D. and Kunte, H.J. A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581 T. Environ. Microbiol. 13 (2011) 1973–1994. [DOI] [PMID: 20849449] |
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[EC 3.5.4.44 created 2017] |
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EC |
4.1.1.86 |
Accepted name: |
diaminobutyrate decarboxylase |
Reaction: |
L-2,4-diaminobutanoate = propane-1,3-diamine + CO2 |
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For diagram of ectoine biosynthesis, click here |
Other name(s): |
DABA DC; L-2,4-diaminobutyrate decarboxylase; L-2,4-diaminobutanoate carboxy-lyase |
Systematic name: |
L-2,4-diaminobutanoate carboxy-lyase (propane-1,3-diamine-forming) |
Comments: |
A pyridoxal-phosphate protein that requires a divalent cation for activity [1]. N4-Acetyl-L-2,4-diaminobutanoate, 2,3-diaminopropanoate, ornithine and lysine are not substrates. Found in the proteobacteria Haemophilus influenzae and Acinetobacter baumannii. In the latter, this enzyme is cotranscribed with the dat gene that encodes EC 2.6.1.76, diaminobutyrate—2-oxoglutarate transaminase, which can supply the substrate for this enzyme. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Yamamoto, S., Tsuzaki, Y., Tougou, K. and Shinoda, S. Purification and characterization of L-2,4-diaminobutyrate decarboxylase
from Acinetobacter calcoaceticus. J. Gen. Microbiol. 138 (1992) 1461–1465. [DOI] [PMID: 1512577] |
2. |
Ikai, H. and Yamamoto, S. Cloning and expression in Escherichia coli of the gene encoding a novel L-2,4-diaminobutyrate decarboxylase of Acinetobacter baumannii. FEMS Microbiol. Lett. 124 (1994) 225–228. [DOI] [PMID: 7813892] |
3. |
Ikai, H. and Yamamoto, S. Identification and analysis of a gene encoding L-2,4-diaminobutyrate:2-ketoglutarate 4-aminotransferase involved in the 1,3-diaminopropane production pathway in Acinetobacter baumannii. J. Bacteriol. 179 (1997) 5118–5125. [DOI] [PMID: 9260954] |
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[EC 4.1.1.86 created 2006] |
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EC |
4.2.1.108 |
Accepted name: |
ectoine synthase |
Reaction: |
(2S)-4-acetamido-2-aminobutanoate = L-ectoine + H2O |
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For diagram of ectoine biosynthesis, click here |
Glossary: |
ectoine = (4S)-2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylate |
Other name(s): |
ectC (gene name); N-acetyldiaminobutyrate dehydratase; N-acetyldiaminobutanoate dehydratase; L-ectoine synthase; 4-N-acetyl-L-2,4-diaminobutanoate hydro-lyase (L-ectoine-forming); N4-acetyl-L-2,4-diaminobutanoate hydro-lyase (L-ectoine-forming) |
Systematic name: |
(2S)-4-acetamido-2-aminobutanoate (L-ectoine-forming) |
Comments: |
Ectoine is an osmoprotectant that is found in halophilic eubacteria. This enzyme is part of the ectoine biosynthesis pathway and only acts in the direction of ectoine formation. cf. EC 3.5.4.44, ectoine hydrolase. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Peters, P., Galinski, E.A. and Truper, H.G. The biosynthesis of ectoine. FEMS Microbiol. Lett. 71 (1990) 157–162. |
2. |
Ono, H., Sawada, K., Khunajakr, N., Tao, T., Yamamoto, M., Hiramoto, M., Shinmyo, A., Takano, M. and Murooka, Y. Characterization of biosynthetic enzymes for ectoine as a compatible
solute in a moderately halophilic eubacterium, Halomonas elongata. J. Bacteriol. 181 (1999) 91–99. [PMID: 9864317] |
3. |
Kuhlmann, A.U. and Bremer, E. Osmotically regulated synthesis of the compatible solute ectoine in
Bacillus pasteurii and related Bacillus spp. Appl. Environ. Microbiol. 68 (2002) 772–783. [DOI] [PMID: 11823218] |
4. |
Louis, P. and Galinski, E.A. Characterization of genes for the biosynthesis of the compatible solute ectoine from Marinococcus halophilus and osmoregulated expression in Escherichia coli. Microbiology 143 (1997) 1141–1149. [DOI] [PMID: 9141677] |
5. |
Schwibbert, K., Marin-Sanguino, A., Bagyan, I., Heidrich, G., Lentzen, G., Seitz, H., Rampp, M., Schuster, S.C., Klenk, H.P., Pfeiffer, F., Oesterhelt, D. and Kunte, H.J. A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581 T. Environ. Microbiol. 13 (2011) 1973–1994. [DOI] [PMID: 20849449] |
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[EC 4.2.1.108 created 2006, modified 2017] |
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