2A06

Bovine cytochrome bc1 complex with stigmatellin bound

2A06 の概要

• エントリーDOI: 10.2210/pdb2a06/pdb
• 関連するPDBエントリー: 1PP9 1PPJ
• 分子名称: Ubiquinol-cytochrome-c reductase complex core protein I, mitochondrial, Ubiquinol-cytochrome c reductase complex 7.2 kDa protein, hexyl beta-D-glucopyranoside, ... (23 entities in total)
• 機能のキーワード: cytochrome bc1, membrane protein, heme protein, rieske iron sulfur protein, cytochrome b, cytochrome c1, complex iii, mitochondrial processing protease, ubiquinone, oxidoreductase, redox enzyme, respiratory chain, stigmatellin
• 由来する生物種: Bos taurus (cattle); 詳細
• タンパク質・核酸の鎖数: 20
• 化学式量合計: 489361.88

構造登録者

Huang, L.S.,Cobessi, D.,Tung, E.Y.,Berry, E.A. (登録日: 2005-06-16, 公開日: 2005-06-21, 最終更新日: 2023-08-23)

主引用文献

Huang, L.S.,Cobessi, D.,Tung, E.Y.,Berry, E.A.
Binding of the Respiratory Chain Inhibitor Antimycin to the Mitochondrial bc(1) Complex: A New Crystal Structure Reveals an Altered Intramolecular Hydrogen-bonding Pattern.
J.Mol.Biol., 351:573-597, 2005

PubMed Abstract: Antimycin A (antimycin), one of the first known and most potent inhibitors of the mitochondrial respiratory chain, binds to the quinone reduction site of the cytochrome bc1 complex. Structure-activity relationship studies have shown that the N-formylamino-salicyl-amide group is responsible for most of the binding specificity, and suggested that a low pKa for the phenolic OH group and an intramolecular H-bond between that OH and the carbonyl O of the salicylamide linkage are important. Two previous X-ray structures of antimycin bound to vertebrate bc1 complex gave conflicting results. A new structure reported here of the bovine mitochondrial bc1 complex at 2.28 A resolution with antimycin bound, allows us for the first time to reliably describe the binding of antimycin and shows that the intramolecular hydrogen bond described in solution and in the small-molecule structure is replaced by one involving the NH rather than carbonyl O of the amide linkage, with rotation of the amide group relative to the aromatic ring. The phenolic OH and formylamino N form H-bonds with conserved Asp228 of cytochrome b, and the formylamino O H-bonds via a water molecule to Lys227. A strong density, the right size and shape for a diatomic molecule is found between the other side of the dilactone ring and the alphaA helix.

PubMed: 16024040
DOI: 10.1016/j.jmb.2005.05.053

実験手法

X-RAY DIFFRACTION (2.1 Å)