FIG. 1.

Proposed pathway for chloromethane metabolism in M. chloromethanicum CM4^T. The pathway was modified from that of Vannelli et al. (45). CmuA, methyltransferase I; CmuB, methyltransferase II; MetF, putative 5,10-methylene-tetrahydrofolate reductase; FolD, putative 5,10-methylene-tetrahydrofolate dehydrogenase/5,10-methenyl-tetrahydrofolate cyclohydrolase; PurU, putative 10-formyl-tetrahydrofolate hydrolase; FDH, formate dehydrogenase; Co^I, corrinoid protein acting as the primary methyl acceptor and thought to be part of CmuA; H⁴ folate, tetrahydrofolate.