2GMJ

Structure of Porcine Electron Transfer Flavoprotein-Ubiquinone Oxidoreductase

2GMJ の概要

• エントリーDOI: 10.2210/pdb2gmj/pdb
• 関連するPDBエントリー: 2GMH
• 分子名称: Electron transfer flavoprotein-ubiquinone oxidoreductase, IRON/SULFUR CLUSTER, FLAVIN-ADENINE DINUCLEOTIDE, ... (5 entities in total)
• 機能のキーワード: electron transfer, flavoprotein, oxidoreductase, ubiquinone
• 由来する生物種: Sus scrofa (pig)
• 細胞内の位置: Mitochondrion inner membrane (By similarity): P55931
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 132572.28

構造登録者

Zhang, J.,Frerman, F.E.,Kim, J.-J.P. (登録日: 2006-04-06, 公開日: 2006-10-17, 最終更新日: 2023-08-30)

主引用文献

Zhang, J.,Frerman, F.E.,Kim, J.J.
Structure of electron transfer flavoprotein-ubiquinone oxidoreductase and electron transfer to the mitochondrial ubiquinone pool.
Proc.Natl.Acad.Sci.Usa, 103:16212-16217, 2006

PubMed Abstract: 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.

PubMed: 17050691
DOI: 10.1073/pnas.0604567103

実験手法

X-RAY DIFFRACTION (2.6 Å)