Specific copper transfer from the Cox17 metallochaperone to both Sco1 and Cox11 in the assembly of yeast cytochrome c oxidase
Specific copper transfer from the Cox17 metallochaperone to both Sco1 and Cox11 in the assembly of yeast cytochrome c oxidase
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DOI：
10.1074/jbc.m404747200
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发表时间：
2004-08-20
影响因子：
4.8
通讯作者：
Winge, DR
中科院分区：
文献类型：
--
作者：
Horng, YC;Cobine, PA;Winge, DR
细胞色素c氧化酶中铜位点的组装涉及一系列辅助蛋白，包括Cox 11，Cox 17和Sco 1。两个线粒体内膜蛋白Cox 11和Sco 1被认为是铜供体的Cu-B和Cu-A位点的细胞色素氧化酶，分别，而Cox 17被认为是铜供体的Sco 1的膜间隙内。在这份报告中，我们表明Cox 17是一个特定的铜供体的Sco 1和Cox 11。使用纯化的蛋白质在体外研究，我们证明直接铜转移从CuCox 17到Sco 1或Cox 11。转移是特异性的，因为不发生转移到异源蛋白质，包括牛血清白蛋白和碳酸酐酶。此外，Cox 17的C57 Y突变体不能将铜转移到Sco 1，但能够将铜转移到Cox 11。酵母细胞质表达系统证实了体外转移研究。可溶性结构域的Sco 1和Cox 11，缺乏线粒体靶向序列和跨膜结构域，在酵母细胞质中表达。这些结构域的代谢严格依赖于Cox 17的共表达。因此，Cox 17代表了一种新的铜分子伴侣，可将铜传递给两种蛋白质。
The assembly of the copper sites in cytochrome c oxidase involves a series of accessory proteins, including Cox11, Cox17, and Sco1. The two mitochondrial inner membrane proteins Cox11 and Sco1 are thought to be copper donors to the Cu-B and Cu-A sites of cytochrome oxidase, respectively, whereas Cox17 is believed to be the copper donor to Sco1 within the intermembrane space. In this report we show Cox17 is a specific copper donor to both Sco1 and Cox11. Using in vitro studies with purified proteins, we demonstrate direct copper transfer from CuCox17 to Sco1 or Cox11. The transfer is specific because no transfer occurs to heterologous proteins, including bovine serum albumin and carbonic anhydrase. In addition, a C57Y mutant of Cox17 fails to transfer copper to Sco1 but is competent for copper transfer to Cox11. The in vitro transfer studies were corroborated by a yeast cytoplasm expression system. Soluble domains of Sco1 and Cox11, lacking the mitochondrial targeting sequence and transmembrane domains, were expressed in the yeast cytoplasm. Metallation of these domains was strictly dependent on the co-expression of Cox17. Thus, Cox17 represents a novel copper chaperone that delivers copper to two proteins.