The oxidized subunit B8 from human complex I adopts a thioredoxin fold
The oxidized subunit B8 from human complex I adopts a thioredoxin fold
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DOI：
10.1016/j.str.2004.06.021
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发表时间：
2004-09-01
期刊：
影响因子：
5.7
通讯作者：
Oschkinat, H
中科院分区：
文献类型：
--
作者：
Brockmann, C;Diehl, A;Oschkinat, H
泛醌氧化还原酶（复合物I）的亚基B8（CI-B8）是细菌复合物I中不存在的几种核编码的额外亚基之一。它的溶液结构显示了硫氧还蛋白折叠与人类硫氧还蛋白突变体C73 S和硫氧还蛋白2 Anabeana sp.有趣的是，这些蛋白质含有活性位点在相同的区域，其中氧化CI-B8的二硫键位于最高的相似性。该二硫键的氧化还原电位为-251.6 mV，与其他硫氧还蛋白样蛋白中的二硫化物的氧化还原电位相当。结构分析揭示了一个表面积，这是专门由高度保守的残基，因此最有可能的复合物I内的亚基相互作用位点。
Subunit B8 from ubiquinone oxidoreductase (complex I) (CI-B8) is one of several nuclear-encoded supernumerary subunits that are not present in bacterial complex I. Its solution structure shows a thioredoxin fold with highest similarities to the human thioredoxin mutant C73S and thioredoxin 2 from Anabeana sp. Interestingly, these proteins contain active sites in the same area, where the disulfide bond of oxidized CI-B8 is located. The redox potential of this disulfide bond is -251.6 mV, comparing well to that of disulfides in other thioredoxin-like proteins. Analysis of the structure reveals a surface area that is exclusively composed of highly conserved residues and thus most likely a subunit interaction site within complex I.