CobW_C

Cobalamin synthesis protein cobW C-terminal domain
CobW_C
SMART accession number:SM00833
Description: CobW proteins are generally found proximal to the trimeric cobaltochelatase subunit CobN, which is essential for vitamin B12 (cobalamin) biosynthesis (PUBMED:12869542). They contain a P-loop nucleotide-binding loop in the N-terminal domain and a histidine-rich region in the C-terminal portion suggesting a role in metal binding, possibly as an intermediary between the cobalt transport and chelation systems. CobW might be involved in cobalt reduction leading to cobalt(I) corrinoids. This entry represents the C-terminal domain found in CobW, as well as in P47K, a Pseudomonas chlororaphis protein needed for nitrile hydratase expression (PUBMED:7765511).
Interpro abstract (IPR011629):

Cobalamin (vitamin B12) is a structurally complex cofactor, consisting of a modified tetrapyrrole with a centrally chelated cobalt. Cobalamin is usually found in one of two biologically active forms: methylcobalamin and adocobalamin. Most prokaryotes, as well as animals, have cobalamin-dependent enzymes, whereas plants and fungi do not appear to use it. In bacteria and archaea, these include methionine synthase, ribonucleotide reductase, glutamate and methylmalonyl-CoA mutases, ethanolamine ammonia lyase, and diol dehydratase [(PUBMED:12869542)]. In mammals, cobalamin is obtained through the diet, and is required for methionine synthase and methylmalonyl-CoA mutase [(PUBMED:17163662)].

There are at least two distinct cobalamin biosynthetic pathways in bacteria [(PUBMED:11153269)]:

Either pathway can be divided into two parts: (1) corrin ring synthesis (differs in aerobic and anaerobic pathways) and (2) adenosylation of corrin ring, attachment of aminopropanol arm, and assembly of the nucleotide loop (common to both pathways) [(PUBMED:11215515)]. There are about 30 enzymes involved in either pathway, where those involved in the aerobic pathway are prefixed Cob and those of the anaerobic pathway Cbi. Several of these enzymes are pathway-specific: CbiD, CbiG, and CbiK are specific to the anaerobic route of S. typhimurium, whereas CobE, CobF, CobG, CobN, CobS, CobT, and CobW are unique to the aerobic pathway of P. denitrificans.

CobW proteins are generally found proximal to the trimeric cobaltochelatase subunit CobN, which is essential for vitamin B12 (cobalamin) biosynthesis [(PUBMED:12869542)]. They contain a P-loop nucleotide-binding loop in the N-terminal domain and a histidine-rich region in the C-terminal portion suggesting a role in metal binding, possibly as an intermediary between the cobalt transport and chelation systems. CobW might be involved in cobalt reduction leading to cobalt(I) corrinoids.

This entry represents the C-terminal domain found in CobW, as well as in P47K (P31521), a Pseudomonas chlororaphis protein needed for nitrile hydratase expression [(PUBMED:7765511)].

Family alignment:
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There are 7757 CobW_C domains in 7756 proteins in SMART's nrdb database.

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