1N61: Crystal Structure Of The Cu,Mo-Co Dehydrogenase (Codh); Dithionite Reduced State

Citation:
Abstract
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.
PDB ID: 1N61Download
MMDB ID: 21518
PDB Deposition Date: 2002/11/8
Updated in MMDB: 2012/10
Experimental Method:
x-ray diffraction
Resolution: 1.3  Å
Source Organism:
Similar Structures:
Biological Unit for 1N61: hexameric; determined by author and by software (PISA)
Molecular Components in 1N61
Label Count Molecule
Proteins (6 molecules)
2
Carbon Monoxide Dehydrogenase Small Chain
Molecule annotation
2
Carbon Monoxide Dehydrogenase Large Chain
Molecule annotation
2
Carbon Monoxide Dehydrogenase Medium Chain
Molecule annotation
Chemicals (11 molecules)
1
1
2
4
3
2
4
2
5
2
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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