Xu Shuai, Andrews Diann, Hill Bruce C
Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L3N6 Canada.
Protein Function Discovery Research Group, Queen's University, Kingston, ON K7L3N6 Canada.
Biochem Biophys Rep. 2015 Aug 14;4:10-19. doi: 10.1016/j.bbrep.2015.08.010. eCollection 2015 Dec.
SCO (ynthesis of ytochrome xidase) proteins are present in prokaryotic and eukaryotic cells, and are often required for efficient synthesis of the respiratory enzyme cytochrome oxidase. The version of SCO (SCO) has much greater affinity for Cu(II) than it does for Cu(I) (Davidson and Hill, 2009), and this has been contrasted to mitochondrial SCO proteins that are characterized as being specific for Cu(I) (Nittis, George and Winge, 2001). This differential affinity has been proposed to reflect the different physiological environments in which these two members of the SCO protein family reside. In this study the affinity of mitochondrial SCO1 from yeast is compared directly to that of SCO . We find that the yeast SCO1 protein has similar preference for Cu(II) over Cu(I), as does SCO. We propose a mechanism for SCO function which would involve high-affinity binding to capture Cu(II), and relatively weak binding of Cu(I) to facilitate copper transfer.
SCO（细胞色素氧化酶合成）蛋白存在于原核细胞和真核细胞中，通常是呼吸酶细胞色素氧化酶高效合成所必需的。SCO（SCO）版本对Cu（II）的亲和力比对Cu（I）的亲和力大得多（Davidson和Hill，2009），这与被认为对Cu（I）具有特异性的线粒体SCO蛋白形成对比（Nittis、George和Winge，2001）。有人提出这种差异亲和力反映了SCO蛋白家族这两个成员所处的不同生理环境。在本研究中，将酵母线粒体SCO1的亲和力与SCO的亲和力进行了直接比较。我们发现酵母SCO1蛋白对Cu（II）的偏好与SCO对Cu（II）的偏好相似。我们提出了一种SCO功能机制，该机制涉及高亲和力结合以捕获Cu（II），以及Cu（I）的相对较弱结合以促进铜转移。
