1zxi

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spinqualitylabelsall models 1zxi, resolution 1.7Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Reconstituted CO dehydrogenase from Oligotropha carboxidovorans

Overview

Carbon monoxide dehydrogenase from the bacterium Oligotropha, carboxidovorans catalyzes the oxidation of CO to CO(2) at a unique, [CuSMoO(2)] cluster. In the bacteria the cluster is assembled, post-translational. The integration of S, and particularly of Cu, is rate, limiting in vivo, which leads to CO dehydrogenase preparations containing, the mature and fully functional enzyme along with forms of the enzyme, deficient in one or both of these elements. The active sites of mature and, immature forms of CO dehydrogenase were converted into a [MoO(3)] centre, by treatment with potassium cyanide. We have established a method, which, rescues 50% of the CO dehydrogenase activity by in vitro reconstitution of, the active site through the supply of sulphide first and subsequently of, Cu(I) under reducing conditions. Immature forms of CO dehydrogenase, isolated from the bacterium, which were deficient in S and/or Cu at the, active site, were similarly activated. X-ray crystallography and electron, paramagnetic resonance spectroscopy indicated that the [CuSMoO(2)] cluster, was properly reconstructed. However, reconstituted CO dehydrogenase, contains mature along with immature forms. The chemical reactions of the, reconstitution of CO dehydrogenase are summarized in a model, which, assumes resulphuration of the Mo-ion at both equatorial positions at a 1:1, molar ratio. One equatorial Mo-S group reacts with Cu(I) in a productive, fashion yielding a mature, functional [CuSMoO(2)] cluster. The other Mo-S, group reacts with Cu(I), then Cu(2)S is released and an oxo group is, introduced from water, yielding an inactive [MoO(3)] centre.

About this Structure

1ZXI is a Protein complex structure of sequences from Oligotropha carboxidovorans with CU, PO4, FES, CUM, MCN and FAD as ligands. Active as Carbon-monoxide dehydrogenase (acceptor), with EC number 1.2.99.2 Full crystallographic information is available from OCA.

Reference

Structural and functional reconstruction in situ of the [CuSMoO2] active site of carbon monoxide dehydrogenase from the carbon monoxide oxidizing eubacterium Oligotropha carboxidovorans., Resch M, Dobbek H, Meyer O, J Biol Inorg Chem. 2005 Aug;10(5):518-28. Epub 2005 Sep 23. PMID:16091936

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