Rurek Michal
Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
Acta Biochim Pol. 2008;55(3):417-33. Epub 2008 Sep 4.
c-type cytochromes are characterized by the presence of two covalent bonds linking heme to apocytochrome and by the heme attachment motif in the apoprotein. Several molecular systems for the maturation of c-type cytochromes have evolved in different organisms. The best characterized are three of them: system I, system II and system III. Heme is synthesized in bacterial cytoplasm, in plastids, and in animal and fungal mitochondria. Therefore the maturation of bacterial and plastid c-type cytochromes involves the transport of heme and apocytochrome from the n-side to the p-side of the respective biological membranes and the formation of the covalent bond at the p-side. It should be underlined that the site of the c-type apocytochrome synthesis is also distinct from the site of its functioning. The aim of this review is to present the current state of knowledge concerning the structure and function of two systems - system I and system II - in the maturation of plant mitochondrial and plastid c-type cytochromes, respectively.
c型细胞色素的特征在于存在将血红素与脱辅基细胞色素连接的两个共价键以及脱辅基蛋白中的血红素附着基序。在不同生物体中已经进化出几种用于c型细胞色素成熟的分子系统。其中研究得最清楚的有三种：系统I、系统II和系统III。血红素在细菌细胞质、质体以及动物和真菌的线粒体中合成。因此，细菌和质体c型细胞色素的成熟涉及血红素和脱辅基细胞色素从各自生物膜的n侧运输到p侧，并在p侧形成共价键。应该强调的是，c型脱辅基细胞色素的合成位点也与其功能位点不同。本综述的目的是分别介绍关于植物线粒体和质体c型细胞色素成熟过程中系统I和系统II这两个系统的结构和功能的当前知识状态。
