1n61

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spinqualitylabelsall models 1n61, resolution 1.3Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of the Cu,Mo-CO Dehydrogenase (CODH); Dithionite reduced state

Overview

The CO dehydrogenase of the eubacterium Oligotropha carboxidovorans is a, 277-kDa Mo- and Cu-containing iron-sulfur flavoprotein. Here, the enzyme's, active site in the oxidized or reduced state, after inactivation with, potassium cyanide or with n-butylisocyanide bound to the active site, has, been reinvestigated by multiple wavelength anomalous dispersion, measurements at atomic resolution, electron spin resonance spectroscopy, and chemical analyses. We present evidence for a dinuclear heterometal, [CuSMoO)OH] cluster in the active site of the oxidized or reduced enzyme, which is prone to cyanolysis. The cluster is coordinated through, interactions of the Mo with the dithiolate pyran ring of molybdopterin, cytosine dinucleotide and of the Cu with the Sgamma of Cys-388, which is, part of the active-site loop VAYRC(388)SFR. The previously reported, active-site structure [Dobbek, H., Gremer, L., Meyer, O. & Huber, R., (1999) Proc. Natl. Acad. Sci. USA 96, 8884-8889] of an Mo with three, oxygen ligands and an SeH-group bound to the Sgamma atom of Cys-388 could, not be confirmed. The structure of CO dehydrogenase with the inhibitor, n-butylisocyanide bound has led to a model for the catalytic mechanism of, CO oxidation which involves a thiocarbonate-like intermediate state. The, dinuclear [CuSMo(O)OH] cluster of CO dehydrogenase establishes a, previously uncharacterized class of dinuclear molybdoenzymes containing, the pterin cofactor.

About this Structure

1N61 is a Protein complex structure of sequences from Oligotropha carboxidovorans with PO4, FES, CUN, 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

Catalysis at a dinuclear [CuSMo(==O)OH] cluster in a CO dehydrogenase resolved at 1.1-A resolution., Dobbek H, Gremer L, Kiefersauer R, Huber R, Meyer O, Proc Natl Acad Sci U S A. 2002 Dec 10;99(25):15971-6. PMID:12475995

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