| cobalt chelatase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Putative cobalt chelatase monomer from Desulvobrio vulgaris. | |||||||||
| Identifiers | |||||||||
| EC no. | 6.6.1.2 | ||||||||
| CAS no. | 81295-49-0 | ||||||||
| 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 | ||||||||
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| Cobalt chelatase, CobT subunit | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | CobT | ||||||||
| Pfam | PF06213 | ||||||||
| InterPro | IPR006538 | ||||||||
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Cobalt chelatase (EC 6.6.1.2) is an enzyme that catalyzes the chemical reaction
- ATP + hydrogenobyrinic acid a,c-diamide + Co + H2O ADP + phosphate + cob(II)yrinic acid a,c-diamide + H
ADP + phosphate + cob(II)yrinic acid a,c-diamide + HThe four substrates of this enzyme are ATP, hydrogenobyrinic acid a,c-diamide, Co, and H2O; its four products are ADP, phosphate, cob(II)yrinic acid a,c-diamide, and H.
The aerobic cobalt chelatase (aerobic cobalamin biosynthesis pathway) consists of three subunits, CobT, CobN (InterPro: IPR003672) and CobS (InterPro: IPR006537).
The macrocycle of vitamin B12 can be complexed with metal via the ATP-dependent reactions in the aerobic pathway (e.g., in Pseudomonas denitrificans) or via ATP-independent reactions of sirohydrochlorin in the anaerobic pathway (e.g., in Salmonella typhimurium). The corresponding cobalt chelatases are not homologous. However, aerobic cobalt chelatase subunits CobN and CobS are homologous to Mg-chelatase subunits BchH and BchI, respectively. CobT, too, has been found to be remotely related to the third subunit of Mg-chelatase, BchD (involved in bacteriochlorophyll synthesis, e.g., in Rhodobacter capsulatus).
This enzyme belongs to the family of ligases, specifically those forming nitrogen-D-metal bonds in coordination complexes. The systematic name of this enzyme class is hydrogenobyrinic-acid-a,c-diamide:cobalt cobalt-ligase (ADP-forming). Other names in common use include hydrogenobyrinic acid a,c-diamide cobaltochelatase, CobNST, and CobNCobST. This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B12) in aerobic bacteria.
See also
References
- Romão, Célia V.; Ladakis, Dimitrios; Lobo, Susana A. L.; Carrondo, Maria A.; Brindley, Amanda A.; Deery, Evelyne; Matias, Pedro M.; Pickersgill, Richard W.; Saraiva, Lígia M.; Warren, Martin J. (4 January 2011). "Evolution in a family of chelatases facilitated by the introduction of active site asymmetry and protein oligomerization". Proceedings of the National Academy of Sciences. 108 (1): 97–102. doi:10.1073/pnas.1014298108. PMC 3017170. PMID 21173279.
- Crouzet J, Cameron B, Cauchois L, Rigault S, Blanche F, Guilhot C, Levy-schil S, Rouyez MC (1991). "Genetic and sequence analyses of a Pseudomonas denitrificans DNA fragment containing two cob genes". J. Bacteriol. 173 (19): 6058–6065. doi:10.1128/jb.173.19.6058-6065.1991. PMC 208352. PMID 1917840.
- Crouzet J, Cameron B, Blanche F, Thibaut D, Debussche L, Couder M (1992). "Assay, purification, and characterization of cobaltochelatase, a unique complex enzyme catalyzing cobalt insertion in hydrogenobyrinic acid a,c-diamide during coenzyme B12 biosynthesis in Pseudomonas denitrificans". J. Bacteriol. 174 (22): 7445–7451. doi:10.1128/jb.174.22.7445-7451.1992. PMC 207441. PMID 1429466.
- Roth JR, Lawrence JG, Bobik TA (1996). "Cobalamin (coenzyme B12): synthesis and biological significance" (PDF). Annu. Rev. Microbiol. 50: 137–181. doi:10.1146/annurev.micro.50.1.137. PMID 8905078. S2CID 36290299. Archived from the original (PDF) on 2019-03-07.
- ^ Willows RD, Al-Karadaghi S, Hansson M, Fodje MN, Hansson A, Olsen JG, Gough S (2001). "Interplay between an AAA module and an integrin I domain may regulate the function of magnesium chelatase". J. Mol. Biol. 311 (1): 111–122. doi:10.1006/jmbi.2001.4834. PMID 11469861.
Further reading
- Debussche L, Couder M, Thibaut D, Cameron B, Crouzet J, Blanche F (1992). "Assay, purification, and characterization of cobaltochelatase, a unique complex enzyme catalyzing cobalt insertion in hydrogenobyrinic acid a,c-diamide during coenzyme B12 biosynthesis in Pseudomonas denitrificans". J. Bacteriol. 174 (22): 7445–51. doi:10.1128/JB.174.22.7445-7451.1992. PMC 207441. PMID 1429466.
- 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.
| Enzymes: Phosphoric ester and nitrogen-metal ligases (EC 6.5-6.6) | |
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| 6.5: Phosphoric Ester | |
| 6.6: Nitrogen-Metal | |
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