Part 5. Molybdenum/Tungsten
Published Online: 15 APR 2006
Copyright © 2006 John Wiley & Sons, Ltd. All rights reserved.
Handbook of Metalloproteins
How to Cite
Dobbek, H., Gremer, L., Meyer, O. and Huber, R. 2006. CO Dehydrogenase. Handbook of Metalloproteins. 5.
- Published Online: 15 APR 2006
Two principal types of CO dehydrogenases have been discovered, which are distinguished by their metal contents, amino acid sequences, molecular masses, and their sensitivity toward dioxygen.
The CODH from the aerobic eubacterium Oligotropha carboxidovorans catalyzes the oxidation of CO with H2O, yielding CO2, two protons, and two electrons. The enzyme is composed of an 88.7-kDa molybdoprotein (L), a 30.2-kDa flavoprotein (M), and a 17.8-kDa iron–sulfur protein (S) and is organized as a dimer of LMS heterotrimers. The active site of CODH consists of a binuclear heterometal [CuSMo(=O)OH] cluster that is prone to cyanolysis. The cluster is coordinated through interactions of the molybdenum with the dithiolate pyran ring of molybdopterin cytosine dinucleotide and of the copper with Sγ of Cys388; the two metals are bridged by a sulfido-ligand. A model for the catalytic cycle involves a thiocarbonate-like intermediate state and includes the transfer of two electrons from Mo through two types of [2Fe–2S]-clusters to the flavin–adenine dinucleotide cofactor.
- carbon monoxide (CO) dehydrogenase (CODH);
- E.C. 188.8.131.52