Sequences of the cobalamin biosynthetic genes cobK, cobL and cobM from Rhodococcus sp. NI86/21.

Sequence analysis of a 5753-bp genomic fragment of Rhodococcus sp. NI86/21 revealed the presence of three homologues of known cobalamin biosynthetic genes. One of these genes encodes a protein showing strong homology with the precorrin-6x reductase (CobK) of Pseudomonas denitrificans. In addition, the rhodococcal homologue of the corrin methyltransferases, CobM from P. denitrificans and CbiF from Salmonella typhimurium, was identified. The protein deduced from a third Rhodococcus gene aligns well with CobL of P. denitrificans and with the protein pair CbiE/CbiT of S. typhimurium, which are involved in corrin methylation and decarboxylation.