EC |
1.3.1.54 |
Accepted name: |
precorrin-6A reductase |
Reaction: |
precorrin-6B + NADP+ = precorrin-6A + NADPH + H+ |
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For diagram of corrin biosynthesis (part 3), click here |
Other name(s): |
precorrin-6X reductase; precorrin-6Y:NADP+ oxidoreductase; CobK |
Systematic name: |
precorrin-6B:NADP+ oxidoreductase |
Comments: |
The enzyme, which participates in the aerobic (late cobalt insertion) pathway of adenosylcobalamin biosynthesis, catalyses the reduction of the double bond between C-18 and C-19 of precorrin-6A. See EC 1.3.1.106, cobalt-precorrin-6A reductase, for the corresponding enzyme that participates in the anaerobic cobalamin biosynthesis pathway. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 137573-72-9 |
References: |
1. |
Blanche, F., Thibaut, D., Famechon, A., Debussche, L., Cameron, B. and Crouzet, J. Precorrin-6X reductase from Pseudomonas denitrificans: purification and characterization of the enzyme and identification of the structural gene. J. Bacteriol. 174 (1992) 1036–1042. [DOI] [PMID: 1732193] |
2. |
Warren, M.J., Raux, E., Schubert, H.L. and Escalante-Semerena, J.C. The biosynthesis of adenosylcobalamin (vitamin B12). Nat. Prod. Rep. 19 (2002) 390–412. [PMID: 12195810] |
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[EC 1.3.1.54 created 1999, modified 2004] |
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EC |
1.3.1.106 |
Accepted name: |
cobalt-precorrin-6A reductase |
Reaction: |
cobalt-precorrin-6B + NAD+ = cobalt-precorrin-6A + NADH + H+ |
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For diagram of anaerobic corrin biosynthesis (part 2), click here |
Other name(s): |
cbiJ (gene name) |
Systematic name: |
cobalt-precorrin-6B:NAD+ oxidoreductase |
Comments: |
The enzyme, which participates in the anaerobic (early cobalt insertion) pathway of adenosylcobalamin biosynthesis, catalyses the reduction of the double bond between C-18 and C-19 of cobalt-precorrin-6A. The enzyme from the bacterium Bacillus megaterium has no activity with NADPH. See EC 1.3.1.54, precorrin-6A reductase, for the corresponding enzyme that participates in the aerobic cobalamin biosynthesis pathway. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Kim, W., Major, T.A. and Whitman, W.B. Role of the precorrin 6-X reductase gene in cobamide biosynthesis in Methanococcus maripaludis. Archaea 1 (2005) 375–384. [PMID: 16243778] |
2. |
Moore, S.J., Lawrence, A.D., Biedendieck, R., Deery, E., Frank, S., Howard, M.J., Rigby, S.E. and Warren, M.J. Elucidation of the anaerobic pathway for the corrin component of cobalamin (vitamin B12). Proc. Natl. Acad. Sci. USA 110 (2013) 14906–14911. [DOI] [PMID: 23922391] |
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[EC 1.3.1.106 created 2014] |
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EC |
2.1.1.195 |
Accepted name: |
cobalt-precorrin-5B (C1)-methyltransferase |
Reaction: |
S-adenosyl-L-methionine + cobalt-precorrin-5B = S-adenosyl-L-homocysteine + cobalt-precorrin-6A |
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For diagram of anaerobic corrin biosynthesis (part 1), click here |
Glossary: |
cobalt-precorrin-6A = cobalt-precorrin-6x |
Other name(s): |
cobalt-precorrin-6A synthase; CbiD |
Systematic name: |
S-adenosyl-L-methionine:cobalt-precorrin-5B C1-methyltransferase |
Comments: |
This enzyme catalyses the C-1 methylation of cobalt-precorrin-5B in the anaerobic (early cobalt insertion) pathway of adenosylcobalamin biosynthesis. See EC 2.1.1.152, precorrin-6A synthase (deacetylating), for the C1-methyltransferase that participates in the aerobic cobalamin biosynthesis pathway. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Roper, J.M., Raux, E., Brindley, A.A., Schubert, H.L., Gharbia, S.E., Shah, H.N. and Warren, M.J. The enigma of cobalamin (Vitamin B12) biosynthesis in Porphyromonas gingivalis. Identification and characterization of a functional corrin pathway. J. Biol. Chem. 275 (2000) 40316–40323. [DOI] [PMID: 11007789] |
2. |
Roessner, C.A., Williams, H.J. and Scott, A.I. Genetically engineered production of 1-desmethylcobyrinic acid, 1-desmethylcobyrinic acid a,c-diamide, and cobyrinic acid a,c-diamide in Escherichia coli implies a role for CbiD in C-1 methylation in the anaerobic pathway to cobalamin. J. Biol. Chem. 280 (2005) 16748–16753. [DOI] [PMID: 15741157] |
3. |
Moore, S.J., Lawrence, A.D., Biedendieck, R., Deery, E., Frank, S., Howard, M.J., Rigby, S.E. and Warren, M.J. Elucidation of the anaerobic pathway for the corrin component of cobalamin (vitamin B12). Proc. Natl. Acad. Sci. USA 110 (2013) 14906–14911. [DOI] [PMID: 23922391] |
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[EC 2.1.1.195 created 2010] |
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