Exploring the catalytic core of complex I by Yarrowia lipolytica yeast genetics
Exploring the catalytic core of complex I by Yarrowia lipolytica yeast genetics
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DOI：
10.1023/a:1010726818165
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发表时间：
2001-06-01
影响因子：
3
通讯作者：
Brandt, U
中科院分区：
文献类型：
--
作者：
Kerscher, S;Kashani-Poor, N;Brandt, U
我们已经开发了解脂耶氏酵母作为模型系统来研究线粒体复合物I，其结合了快速和方便的酵母遗传学的应用与其非常稳定的复合物I的高效结构和功能分析，通过His标签亲和纯化以高产率分离。在基于复合物I和[NiFe]氢化酶之间同源性的结构模型的指导下，突变分析揭示了49 kDa亚基在复合物I中起着中心功能作用。我们建议，复合物I的催化核心的关键部分已经从[NiFe]氢化酶的氢反应位点演变而来，并且铁硫簇N2位于49 kDa和PSST亚基之间的界面处。这些研究结果是完全一致的“半醌开关”的机制，根据该机制，在复杂的I中的电子和质子转移的耦合是通过一个单一的集成泵，包括集群N2，底物泛醌的结合位点，和一个紧密结合的醌或醌基团。
We have developed Yarrowia lipolytica as a model system to study mitochondrial complex I that combines the application of fast and convenient yeast genetics with efficient structural and functional analysis of its very stable complex I isolated by his-tag affinity purification with high yield. Guided by a structural model based on homologies between complex I and [NiFe] hydrogenases mutational analysis revealed that the 49 kDa subunit plays a central functional role in complex I. We propose that critical parts of the catalytic core of complex I have evolved from the hydrogen reactive site of [NiFe] hydrogenases and that iron-sulfur cluster N2 resides at the interface between the 49 kDa and PSST subunits. These findings are in full agreement with the "semiquinone switch" mechanism according to which coupling of electron and proton transfer in complex I is achieved by a single integrated pump comprising cluster N2, the binding site for substrate ubiquinone, and a tightly bound quinone or quinoid group.