User:Cboursnell/Sandbox/2-ph phosp

2-phosphosulpholactate phosphatase (ComB; EC) is a magnesium-dependent acid phosphatase that catalyzes the second step in coenzyme M (CoM; 2-mercaptoethanesulphonic acid) biosynthesis, namely, the hydrolysis of (2R)-2-phospho-3-sulpholactate to yield (2R)-3-sulpholactate and phosphate. CoM is an essential cofactor that acts as the terminal methyl carrier in methanogenesis. Homologues of ComB have been identified in all available cyanobacterial genome sequences and in genomes from phylogenetically diverse bacteria and archaea. However, many of these organisms lack homologues of other CoM biosynthetic genes. ComB has a complex alpha/beta topology. The monomer is composed of two domains thought to be related by a common ancestral gene, plus a C-terminal helical and beta-hairpin region.