Biology:Sirohydrochlorin cobaltochelatase

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Short description: Enzyme
sirohydrochlorin cobaltochelatase
Identifiers
EC number4.99.1.3
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

The enzyme sirohydrochlorin cobaltochelatase (EC 4.99.1.3) catalyzes the reaction

cobalt-sirohydrochlorin + 2 H+ = sirohydrochlorin + Co2+
Sirohydrochlorin substrate of the enzme

In the forward direction of reactions towards cobalamin in anaerobic bacteria, the two substrates of this enzyme are sirohydrochlorin and Co2+; its two products are cobalt-sirohydrochlorin and H+.

This enzyme belongs to the family of lyases, specifically the "catch-all" class of lyases that do not fit into any other sub-class. The systematic name of this enzyme class is cobalt-sirohydrochlorin cobalt-lyase (sirohydrochlorin-forming). Other names in common use include CbiK, CbiX, CbiXS, anaerobic cobalt chelatase, cobaltochelatase [ambiguous], and sirohydrochlorin cobalt-lyase (incorrect). This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B12) in bacteria such as Salmonella typhimurium and Bacillus megaterium. It has also been identified as the enzyme which inserts nickel into sirohydrochlorin in the biosynthesis of cofactor F430, reaction EC 4.99.1.11.[1]

See also

Structural studies

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1TJN and 2DJ5.

References

Further reading

  • "Common chelatase design in the branched tetrapyrrole pathways of heme and anaerobic cobalamin synthesis". Biochemistry 38 (33): 10660–9. August 1999. doi:10.1021/bi9906773. PMID 10451360. 
  • "A story of chelatase evolution: identification and characterization of a small 13-15-kDa "ancestral" cobaltochelatase (CbiXS) in the archaea". The Journal of Biological Chemistry 278 (25): 22388–95. June 2003. doi:10.1074/jbc.M302468200. PMID 12686546. 
  • "The biosynthesis of adenosylcobalamin (vitamin B12)". Natural Product Reports 19 (4): 390–412. August 2002. doi:10.1039/b108967f. PMID 12195810.