Structure of the zinc-binding domain of an essential component of the hepatitis C virus replicase
Structure of the zinc-binding domain of an essential component of the hepatitis C virus replicase
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DOI：
10.1038/nature03580
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发表时间：
2005-05-19
期刊：
影响因子：
64.8
通讯作者：
Rice, CM
中科院分区：
文献类型：
--
作者：
Tellinghuisen, TL;Marcotrigiano, J;Rice, CM
丙型肝炎病毒（HCV）是一种人类病原体，影响近3%的世界人口（1）。慢性感染可导致肝硬化和肝癌。HCV的RNA复制机器是一个多亚基膜结合复合物。非结构蛋白NS 5A是HCV复制酶的活性成分（2，3），也是复制的关键调节因子（2，4）和从先天免疫到失调细胞生长的细胞过程的调节因子（5，6）。NS 5A是一种大的磷蛋白（56 - 58 kDa），在其氨基末端具有促进膜结合的两亲性α-螺旋（7-9）。在该螺旋区域之后，NS 5A被组织成三个结构域（10）。N-末端结构域（结构域I）与每个蛋白质分子的单个锌原子配位（10）。破坏NS 5A的膜锚（7，8）或锌结合（10）的突变对于RNA复制是致命的。然而，由于缺乏关于这种多功能蛋白的结构信息，探索NS 5A在复制中的作用受到了阻碍。在这里，我们报告的结构NS 5A域I在2.5埃分辨率，其中包含一个新的折叠，一个新的锌配位基序和二硫键。我们使用分子表面分析，建议蛋白质，RNA和膜相互作用的网站的位置。
Hepatitis C virus (HCV) is a human pathogen affecting nearly 3% of the world's population(1). Chronic infections can lead to cirrhosis and liver cancer. The RNA replication machine of HCV is a multi-subunit membrane-associated complex. The nonstructural protein NS5A is an active component of HCV replicase(2,3), as well as a pivotal regulator of replication(2,4) and a modulator of cellular processes ranging from innate immunity to dysregulated cell growth(5,6). NS5A is a large phosphoprotein (56 - 58 kDa) with an amphipathic alpha-helix at its amino terminus that promotes membrane association(7-9). After this helix region, NS5A is organized into three domains(10). The N-terminal domain ( domain I) coordinates a single zinc atom per protein molecule(10). Mutations disrupting either the membrane anchor(7,8) or zinc binding(10) of NS5A are lethal for RNA replication. However, probing the role of NS5A in replication has been hampered by a lack of structural information about this multifunctional protein. Here we report the structure of NS5A domain I at 2.5-angstrom resolution, which contains a novel fold, a new zinc-coordination motif and a disulphide bond. We use molecular surface analysis to suggest the location of protein-, RNA- and membrane-interaction sites.