Sirohydrochlorin cobaltochelatase

sirohydrochlorin cobaltochelatase
Identifiers
EC no.	4.99.1.3
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a sirohydrochlorin cobaltochelatase (EC 4.99.1.3) is an enzyme that catalyzes the chemical reaction

cobalt-sirohydrochlorin + 2 H⁺ $\rightleftharpoons$ sirohydrochlorin + Co²⁺

Thus, the two substrates of this enzyme are cobalt-sirohydrochlorin and H⁺, whereas its two products are sirohydrochlorin and Co²⁺.

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 participates in porphyrin and chlorophyll metabolism.

Structural studies

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

References

• Schubert HL, Raux E, Wilson KS, Warren MJ (1999). "Common chelatase design in the branched tetrapyrrole pathways of heme and anaerobic cobalamin synthesis". Biochemistry. 38 (33): 10660–9. doi:10.1021/bi9906773. PMID 10451360.
• Brindley AA, Raux E, Leech HK, Schubert HL, Warren MJ (2003). "A story of chelatase evolution: identification and characterization of a small 13-15-kDa "ancestral" cobaltochelatase (CbiXS) in the archaea". J. Biol. Chem. 278 (25): 22388–95. doi:10.1074/jbc.M302468200. PMID 12686546.{{cite journal}}: CS1 maint: unflagged free DOI (link)
• Warren MJ, Raux E, Schubert HL, Escalante-Semerena JC (2002). "The biosynthesis of adenosylcobalamin (vitamin B₁₂)". Nat. Prod. Rep. 19 (4): 390–412. doi:10.1039/b108967f. PMID 12195810.