2XVZ
Cobalt chelatase CbiK (periplasmatic) from Desulvobrio vulgaris Hildenborough (co-crystallized with cobalt)
Summary for 2XVZ
| Entry DOI | 10.2210/pdb2xvz/pdb |
| Descriptor | CHELATASE, PUTATIVE, PROTOPORPHYRIN IX CONTAINING FE, COBALT (II) ION, ... (9 entities in total) |
| Functional Keywords | metal binding protein |
| Biological source | DESULFOVIBRIO VULGARIS |
| Cellular location | Periplasm: Q72EC8 |
| Total number of polymer chains | 1 |
| Total formula weight | 30578.46 |
| Authors | Romao, C.V.,Lobo, S.A.L.,Carrondo, M.A.,Saraiva, L.M.,Matias, P.M. (deposition date: 2010-10-28, release date: 2010-12-22, Last modification date: 2024-05-08) |
| Primary citation | Romao, C.V.,Ladakis, D.,Lobo, S.A.L.,Carrondo, M.A.,Brindley, A.A.,Deery, E.,Matias, P.M.,Pickersgill, R.W.,Saraiva, L.M.,Warren, M.J. Evolution in a Family of Chelatases Facilitated by the Introduction of Active Site Asymmetry and Protein Oligomerization. Proc.Natl.Acad.Sci.USA, 108:97-, 2011 Cited by PubMed Abstract: The class II chelatases associated with heme, siroheme, and cobalamin biosynthesis are structurally related enzymes that insert a specific metal ion (Fe(2+) or Co(2+)) into the center of a modified tetrapyrrole (protoporphyrin or sirohydrochlorin). The structures of two related class II enzymes, CbiX(S) from Archaeoglobus fulgidus and CbiK from Salmonella enterica, that are responsible for the insertion of cobalt along the cobalamin biosynthesis pathway are presented in complex with their metallated product. A further structure of a CbiK from Desulfovibrio vulgaris Hildenborough reveals how cobalt is bound at the active site. The crystal structures show that the binding of sirohydrochlorin is distinctly different to porphyrin binding in the protoporphyrin ferrochelatases and provide a molecular overview of the mechanism of chelation. The structures also give insights into the evolution of chelatase form and function. Finally, the structure of a periplasmic form of Desulfovibrio vulgaris Hildenborough CbiK reveals a novel tetrameric arrangement of its subunits that are stabilized by the presence of a heme b cofactor. Whereas retaining colbaltochelatase activity, this protein has acquired a central cavity with the potential to chaperone or transport metals across the periplasmic space, thereby evolving a new use for an ancient protein subunit. PubMed: 21173279DOI: 10.1073/PNAS.1014298108 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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