IUBMB Enzyme Nomenclature


Accepted name: precorrin-6A synthase (deacetylating)

Reaction: S-adenosyl-L-methionine + precorrin-5 + H2O = S-adenosyl-L-homocysteine + precorrin-6A + acetate

For diagram click here and mechanism here.

Other name(s): precorrin-6X synthase (deacetylating); CobF

Systematic name: S-adenosyl-L-methionine:precorrin-5 C1-methyltransferase (deacetylating)

Comments: The enzyme, which participates in the aerobic (late cobalt insertion) cobalamin biosythesis pathway, catalyses two reactions -the methylation of carbon C1 of precorrin-5, and its deacetylation, forming precorrin-6A. See EC, cobalt-precorrin-5B (C1)-methyltransferase, for the C1-methyltransferase that participates in the anaerobic cobalamin biosynthesis pathway.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Debussche, L., Thibaut, D., Cameron, B., Crouzet, J. and Blanche, F. Biosynthesis of the corrin macrocycle of coenzyme B12 in Pseudomonas denitrificans. J. Bacteriol. 175 (1993) 7430-7440. [PMID: 8226690]

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]

[EC created 2004]

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