A copper(I) protein possibly involved in the assembly of CuA center of bacterial cytochrome c oxidase
A copper(I) protein possibly involved in the assembly of CuA center of bacterial cytochrome c oxidase
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DOI：
10.1073/pnas.0406150102
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发表时间：
2005-03-15
影响因子：
11.1
通讯作者：
Mangani, S
中科院分区：
文献类型：
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作者：
Banci, L;Bertini, I;Mangani, S
Cox 17和Sco 1是真核细胞色素c氧化酶正确组装所需的辅助蛋白。与Sco 1不同的是，Cox 17的直系同源物仅在真核生物中发现。我们浏览了细菌基因组，以搜索功能等同于Cox 17的蛋白质，我们确定了一类功能未知的蛋白质，它们与细菌Sco 1基因具有保守的基因邻域，所有这些蛋白质都共享一个潜在的金属结合基序H（M）X10 MX21 HXM。这组的两个成员，DR 1885从耐辐射球菌和CC 3502从新月柄杆菌，表达，并与铜的相互作用进行了研究。前一种蛋白质的溶液结构和扩展的X射线吸收精细结构数据表明，该蛋白质通过一个组氨酸和三个Mets在一个铜氧还蛋白样折叠中结合铜（I）。铜结合位点的表面位置以及配位的类型很好地为金属转移化学做好了准备，这表明DR 1885可能转移铜，在细菌中扮演Cox 17的角色。根据我们的研究结果，提出了一个可能的途径铜交付的Cu-A中心的细菌。
Sco1 and Cox17 are accessory proteins required for the correct assembly of eukaryotic cytochrome c oxidase. At variance with Sco1, Cox17 orthologs are found only in eukaryotes. We browsed bacterial genomes to search proteins functionally equivalent to Cox17, and we identified a class of proteins of unknown function displaying a conserved gene neighborhood to bacterial Sco1 genes, all sharing a potential metal binding motif H(M)X10MX21HXM. Two members of this group, DR1885 from Deinococcus radiodurans and CC3502 from Caulobacter crescentus, were expressed, and their interaction with copper was investigated. The solution structure and extended x-ray absorption fine structure data on the former protein reveal that the protein binds copper(I) through a histidine and three Mets in a cupredoxin-like fold. The surface location of the copper-binding site as well as the type of coordination are well poised for metal transfer chemistry, suggesting that DR1885 might transfer copper, taking the role of Cox17 in bacteria. On the basis of our results, a possible pathway for copper delivery to the Cu-A center in bacteria is proposed.