Structure of arterivirus nsp4 -: The smallest chymotrypsin-like proteinase with an α/β C-terminal extension and alternate conformations of the oxyanion hole
Structure of arterivirus nsp4 -: The smallest chymotrypsin-like proteinase with an α/β C-terminal extension and alternate conformations of the oxyanion hole
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DOI：
10.1074/jbc.m206978200
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发表时间：
2002-10-18
影响因子：
4.8
通讯作者：
James, MNG
中科院分区：
文献类型：
--
作者：
Barrette-Ng, IH;Ng, KKS;James, MNG
动脉病毒是有包膜的正链RNA病毒，包括对养猪业和马养殖业具有重大经济意义的病原体。动脉病毒复制酶基因编码两个大的前体多蛋白，由病毒主要蛋白酶非结构蛋白4(NSP4)处理。动脉病毒原型马动脉炎病毒的21 kDa NSP4的三维结构已被确定为2.0埃分辨率。NSP4采用已知最小的类糜蛋白酶折叠，由Ser-120、His-39和Asp-65组成的典型催化三联体，以及一个可能在介导蛋白质-蛋白质相互作用中发挥作用的新的α/βC末端延伸域。在不对称单元的不同拷贝的NSP4中，氧阴离子空穴要么采用塌陷的非活性构象，要么采用标准的活性构象，这可能是一种新的调节蛋白水解酶活性的途径。
Arteriviruses are enveloped, positive-stranded RNA viruses and include pathogens of major economic concern to the swine- and horse-breeding industries. The arterivirus replicase gene encodes two large precursor polyproteins that are processed by the viral main proteinase nonstructural protein 4 (nsp4). The three-dimensional structure of the 21-kDa nsp4 from the arterivirus prototype equine arteritis virus has been determined to 2.0 Angstrom resolution. Nsp4 adopts the smallest known chymotrypsin-like fold with a canonical catalytic triad of Ser-120, His-39, and Asp-65, as well as a novel alpha/beta C-terminal extension domain that may play a role in mediating protein-protein interactions. In different copies of nsp4 in the asymmetric unit, the oxyanion hole adopts either a collapsed inactive conformation or the standard active conformation, which may be a novel way of regulating proteolytic activity.