2gmh

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spinqualitylabelsall models 2gmh, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Structure of Porcine Electron Transfer Flavoprotein-Ubiquinone Oxidoreductase in Complexed with Ubiquinone

Overview

Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a, 4Fe4S flavoprotein located in the inner mitochondrial membrane. It, catalyzes ubiquinone (UQ) reduction by ETF, linking oxidation of fatty, acids and some amino acids to the mitochondrial respiratory chain., Deficiencies in ETF or ETF-QO result in multiple acyl-CoA dehydrogenase, deficiency, a human metabolic disease. Crystal structures of ETF-QO with, and without bound UQ were determined, and they are essentially identical., The molecule forms a single structural domain. Three functional regions, bind FAD, the 4Fe4S cluster, and UQ and are closely packed and share, structural elements, resulting in no discrete structural domains. The, UQ-binding pocket consists mainly of hydrophobic residues, and UQ binding, differs from that of other UQ-binding proteins. ETF-QO is a monotopic, integral membrane protein. The putative membrane-binding surface contains, an alpha-helix and a beta-hairpin, forming a hydrophobic plateau. The, UQ-flavin distance (8.5 A) is shorter than the UQ-cluster distance (18.8, A), and the very similar redox potentials of FAD and the cluster strongly, suggest that the flavin, not the cluster, transfers electrons to UQ. Two, possible electron transfer paths can be envisioned. First, electrons from, the ETF flavin semiquinone may enter the ETF-QO flavin one by one, followed by rapid equilibration with the cluster. Alternatively, electrons, may enter via the cluster, followed by equilibration between centers. In, both cases, when ETF-QO is reduced to a two-electron reduced state (one, electron at each redox center), the enzyme is primed to reduce UQ to, ubiquinol via FAD.

About this Structure

2GMH is a Single protein structure of sequence from Sus scrofa with BHG, NA, SF4, FAD, UQ5 and EDO as ligands. Active as Electron-transferring-flavoprotein dehydrogenase, with EC number 1.5.5.1 Full crystallographic information is available from OCA.

Reference

Structure of electron transfer flavoprotein-ubiquinone oxidoreductase and electron transfer to the mitochondrial ubiquinone pool., Zhang J, Frerman FE, Kim JJ, Proc Natl Acad Sci U S A. 2006 Oct 31;103(44):16212-7. Epub 2006 Oct 18. PMID:17050691

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