For diagram of anaerobic corrin biosynthesis (part 1), click here
CbiH60 (gene name)
S-adenosyl-L-methionine:cobalt-factor III 17-methyltransferase (ring contracting)
Isolated from Bacillus megaterium. The enzyme catalyses both methylation at C-17 and ring contraction. Contains a [4Fe-4S] cluster. It can also convert cobalt-precorrin-3 to cobalt-precorrin-4. The reductant may be thioredoxin.
Moore, S.J., Biedendieck, R., Lawrence, A.D., Deery, E., Howard, M.J., Rigby, S.E. and Warren, M.J. Characterization of the enzyme CbiH60 involved in anaerobic ring contraction of the cobalamin (vitamin B12) biosynthetic pathway. J. Biol. Chem.288 (2013) 297–305. [PMID: 23155054]