1fft
From Proteopedia
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The structure of ubiquinol oxidase from Escherichia coli
Overview
Cell respiration is catalyzed by the heme-copper oxidase superfamily of, enzymes, which comprises cytochrome c and ubiquinol oxidases. These, membrane proteins utilize different electron donors through dissimilar, access mechanisms. We report here the first structure of a ubiquinol, oxidase, cytochrome bo3, from Escherichia coli. The overall structure of, the enzyme is similar to those of cytochrome c oxidases; however, the, membrane-spanning region of subunit I contains a cluster of polar residues, exposed to the interior of the lipid bilayer that is not present in the, cytochrome c oxidase. Mutagenesis studies on these residues strongly, suggest that this region forms a quinone binding site. A sequence, comparison of this region with known quinone binding sites in other, membrane proteins shows remarkable similarities. In light of these, findings we suggest specific roles for these polar residues in electron, and proton transfer in ubiquinol oxidase.
About this Structure
1FFT is a Protein complex structure of sequences from Escherichia coli with CU, HEM and HEO as ligands. Full crystallographic information is available from OCA.
Reference
The structure of the ubiquinol oxidase from Escherichia coli and its ubiquinone binding site., Abramson J, Riistama S, Larsson G, Jasaitis A, Svensson-Ek M, Laakkonen L, Puustinen A, Iwata S, Wikstrom M, Nat Struct Biol. 2000 Oct;7(10):910-7. PMID:11017202
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