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3i01
From Proteopedia
| 3i01, resolution 2.15Å () | |||||||||
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| Ligands: | , , , , , , | ||||||||
| Activity: | CO-methylating acetyl-CoA synthase, with EC number 2.3.1.169 | ||||||||
| Related: | 1mjg, 3i04 | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Contents |
Native structure of bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase from Moorella thermoacetica, water-bound C-cluster.
Nickel-containing carbon monoxide dehydrogenases (CODHs) reversibly catalyze the oxidation of carbon monoxide to carbon dioxide and are of vital importance in the global carbon cycle. The unusual catalytic CODH C-cluster has been crystallographically characterized as either a NiFe<sub>4</sub>S<sub>4</sub> or a NiFe<sub>4</sub>S<sub>5</sub> metal center, the latter containing a fifth, additional sulfide that bridges Ni and a unique Fe site. To determine whether this bridging sulfide is catalytically relevant and to further explore the mechanism of the C-cluster, we obtained crystal structures of the 310 kDa bifunctional CODH/acetyl-CoA synthase complex from <i>Moorella thermoacetica</i> bound both with a substrate H<sub>2</sub>O/OH<sup>-</sup> molecule and a cyanide inhibitor. X-ray diffraction data were collected from native crystals and from identical crystals soaked in a solution containing potassium cyanide. In both structures, the substrate H<sub>2</sub>O/OH<sup>-</sup> molecule exhibits binding to the unique Fe site of the C-cluster. We also observe cyanide binding in a bent conformation to Ni of the C-cluster, adjacent the substrate H<sub>2</sub>O/OH<sup>-</sup> molecule. Importantly, the bridging sulfide is not present in either structure. As these forms of the C-cluster represent the coordination environment immediately before the reaction takes place, our findings do not support a fifth, bridging sulfide playing a catalytic role in the enzyme mechanism. The crystal structures presented here, along with recent structures of CODHs from other organisms, have led us towards a unified mechanism for CO oxidation by the C-cluster, the catalytic center of an environmentally important enzyme.
Crystallographic snapshots of cyanide- and water-bound C-clusters from bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase., Kung Y, Doukov TI, Seravalli J, Ragsdale SW, Drennan CL, Biochemistry. 2009 Jul 7. PMID:19583207
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
3i01 is a 8 chain structure with sequence from Moorella thermoacetica. Full crystallographic information is available from OCA.
See Also
Reference
- Kung Y, Doukov TI, Seravalli J, Ragsdale SW, Drennan CL. Crystallographic snapshots of cyanide- and water-bound C-clusters from bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase. Biochemistry. 2009 Jul 7. PMID:19583207 doi:10.1021/bi900574h
Categories: CO-methylating acetyl-CoA synthase | Moorella thermoacetica | Doukov, T I. | Drennan, C L. | Kung, Y. | Carbon dioxide fixation | Electron transport | Iron | Iron-sulfur | Metal-binding | Nickel | Oxidoreductase | Oxidoreductase-transferase complex | Protein-protein complex | Transferase | Transport
