Carr Heather S, George Graham N, Winge Dennis R
University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA.
J Biol Chem. 2002 Aug 23;277(34):31237-42. doi: 10.1074/jbc.M204854200. Epub 2002 Jun 12.
Cox11 is a protein essential for respiratory growth and has been implicated in the assembly of the Cu(B) site of cytochrome c oxidase. In the present study, we demonstrate that Cox11 is a copper-binding protein. The soluble C-terminal domain of Cox11 forms a dimer that coordinates one Cu(I) per monomer via three thiolate ligands. The two Cu(I) ions in the dimer exist in a binuclear cluster and appear to be ligated by three conserved Cys residues. Mutation of any of these Cys residues reduces Cu(I) binding and confers respiratory incompetence. Cytochrome c oxidase activity is reduced in these mutants. Thus, the residues important for Cu(I) binding correlate with in vivo function, suggesting that Cu(I) binding is important in Cox11 function.
Cox11是呼吸生长所必需的一种蛋白质，并且与细胞色素c氧化酶的铜（B）位点组装有关。在本研究中，我们证明Cox11是一种铜结合蛋白。Cox11的可溶性C末端结构域形成二聚体，每个单体通过三个硫醇盐配体配位一个Cu（I）。二聚体中的两个Cu（I）离子以双核簇的形式存在，并且似乎由三个保守的半胱氨酸残基连接。这些半胱氨酸残基中的任何一个发生突变都会降低Cu（I）的结合并导致呼吸功能不全。这些突变体中的细胞色素c氧化酶活性降低。因此，对Cu（I）结合重要的残基与体内功能相关，表明Cu（I）结合在Cox11功能中很重要。
