Reaction: S-adenosyl-L-methionine + precorrin-4 = S-adenosyl-L-homocysteine + precorrin-5
For diagram click here.
Other name(s): precorrin-3 methylase; CobM
Systematic name: S-adenosyl-L-methionine:precorrin-4 C11 methyltransferase
Comments: In the aerobic (late cobalt insertion) cobalamin biosythesis pathway, four enzymes are involved in the conversion of precorrin-3A to precorrin-6A. The first of the four steps is carried out by EC 1.14.13.83, precorrin-3B synthase (CobG), yielding precorrin-3B as the product. This is followed by three methylation reactions, which introduce a methyl group at C-17 (CobJ; EC 2.1.1.131), C-11 (CobM; EC 2.1.1.133) and C-1 (CobF; EC 2.1.1.152) of the macrocycle, giving rise to precorrin-4, precorrin-5, and precorrin-6A, respectively. See EC 2.1.1.271, cobalt-precorrin-4 methyltransferase, for the C11-methyltransferase enzyme that participates in the anaerobic cobalamin biosynthesis pathway.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 152787-65-0
References:
1. Crouzet, J., Cameron, B., Cauchois, L., Rigault, S., Rouyez, M.C., Blanche, F., Thibaut D., Debussche, L. Genetic and sequence analysis of an 8.7-kilobase Pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid. J. Bacteriol. 172 (1990) 5980-5990. [PMID: 2211521]
2. Roth, J.R., Lawrence, J.G., Rubenfield, M., Kieffer-Higgins, S., Church, G.M. Characterization of the cobalamin (vitamin B12) biosynthetic genes of Salmonella typhimurium. J. Bacteriol. 175 (1993) 3303-3316. [PMID: 8501034]