Inhibitor-complexed structures of the cytochrome bc1 from the photosynthetic bacterium Rhodobacter sphaeroides
Inhibitor-complexed structures of the cytochrome bc1 from the photosynthetic bacterium Rhodobacter sphaeroides
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DOI：
10.1074/jbc.m708608200
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发表时间：
2008-02-01
影响因子：
4.8
通讯作者：
Xia, Di
中科院分区：
文献类型：
--
作者：
Esser, Lothar;Elberry, Maria;Xia, Di
细胞色素bc(1)复合体（bc(1)）是通过耦合电子转移到质子易位的质子动力跨膜的主要贡献者。测定了光合紫色细菌球形Rhodobacter sphaeroides（Rsbc(1)）的野生型和突变型bc(1)配合物的晶体结构，分别用喹啉氧化（Q(P)）位点抑制剂stimatellin单独或与醌还原（Q(N)）位点抑制剂antiycin联合稳定。高质量的电子密度允许将新的金属结合位点分配到细胞色素c(1)亚基和许多脂质和洗涤剂分子上。Rsbc(1)与其线粒体对应体之间的结构差异主要是膜外的，这为理解细菌亚基中主要较长序列的功能提供了基础。bc(1)复合物的功能意义来自于对不同晶体形式的10个独立分子的分析以及与线粒体复合物的比较。
The cytochrome bc(1) complex (bc(1)) is a major contributor to the proton motive force across the membrane by coupling electron transfer to proton translocation. The crystal structures of wild type and mutant bc(1) complexes from the photosynthetic purple bacterium Rhodobacter sphaeroides(Rsbc(1)), stabilized with the quinol oxidation (Q(P)) site inhibitor stigmatellin alone or in combination with the quinone reduction (Q(N)) site inhibitor antimycin, were determined. The high quality electron density permitted assignments of a new metal-binding site to the cytochrome c(1) subunit and a number of lipid and detergent molecules. Structural differences between Rsbc(1) and its mitochondrial counterparts are mostly extra membranous and provide a basis for understanding the function of the predominantly longer sequences in the bacterial subunits. Functional implications for the bc(1) complex are derived from analyses of 10 independent molecules in various crystal forms and from comparisons with mitochondrial complexes.