Taxonomic distribution of proteins containing Ald_Xan_dh_C domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing Ald_Xan_dh_C domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Crystal structure and mechanism of CO dehydrogenase, a molybdo iron-sulfurflavoprotein containing S-selanylcysteine.

Dobbek H, Gremer L, Meyer O, Huber R
Proc Natl Acad Sci U S A. 1999; 96: 8884-9

CO dehydrogenase from the aerobic bacterium Oligotropha carboxidovoranscatalyzes the oxidation of CO with H(2)O, yielding CO(2), two electrons,and two H(+). Its crystal structure in the air-oxidized form has beendetermined to 2.2 A. The active site of the enzyme, which containsmolybdenum with three oxygen ligands, molybdopterin-cytosine dinucleotideand S-selanylcysteine, delivers the electrons to an intramolecularelectron transport chain composed of two types of [2Fe-2S] clusters andflavin-adenine dinucleotide. CO dehydrogenase is composed of an 88.7-kDamolybdoprotein (L), a 30. 2-kDa flavoprotein (M), and a 17.8-kDairon-sulfur protein (S). It is organized as a dimer of LMS heterotrimersand resembles xanthine dehydrogenase/oxidase in many, but not all,aspects. A mechanism based on a structure with the bound suicide-substratecyanide is suggested and displays the necessity of S-selanylcysteine forthe catalyzed reaction.

Crystal structure of the xanthine oxidase-related aldehyde oxido-reductasefrom D. gigas.

Romao MJ, Archer M, Moura I, Moura JJ, LeGall J, Engh R, Schneider M, Hof P, Huber R
Science. 1995; 270: 1170-6

The crystal structure of the aldehyde oxido-reductase (Mop) from thesulfate reducing anaerobic Gram-negative bacterium Desulfovibrio gigas hasbeen determined at 2.25 A resolution by multiple isomorphous replacementand refined. The protein, a homodimer of 907 amino acid residues subunits,is a member of the xanthine oxidase family. The protein contains amolybdopterin cofactor (Mo-co) and two different [2Fe-2S] centers. It isfolded into four domains of which the first two bind the iron sulfurcenters and the last two are involved in Mo-co binding. Mo-co is amolybdenum molybdopterin cytosine dinucleotide. Molybdopterin forms atricyclic system with the pterin bicycle annealed to a pyran ring. Themolybdopterin dinucleotide is deeply buried in the protein. Thecis-dithiolene group of the pyran ring binds the molybdenum, which iscoordinated by three more (oxygen) ligands.