Three-dimensional structure of a monomeric form of a retroviral protease
Three-dimensional structure of a monomeric form of a retroviral protease
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DOI：
10.1016/j.jmb.2003.08.049
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发表时间：
2003-10-31
影响因子：
5.6
通讯作者：
Hrabal, R
中科院分区：
文献类型：
--
作者：
Veverka, V;Bauerová, H;Hrabal, R
Mason-Pfizer猴病毒Gag多聚蛋白组装成未成熟衣壳和被编码的蛋白酶切割是在时间和空间上分离的过程，使病毒成为研究蛋白酶激活的一个特别有用的模型。在这里，我们提供了12 kDa M-PMV蛋白酶(Wt12PR)和Cys7Ala/Asp26Asn/Cys106Ala的全折叠单体的高分辨核磁共振结构。突变株(12株PRD26N/C7A/C106A)。Wt 12PR和12PRD26N/C7A/C106A的整体结构都遵循其他逆转录病毒蛋白的保守结构基序。与逆转录病毒蛋白的典型折叠最显著的区别是没有界面的β-折叠，这导致了稳定M-PMV PR二聚体的主力的丧失。通过添加底物或抑制剂，单体-二聚体的平衡可以向有利于二聚体的方向移动，部分弥补了β-折叠的缺失作用。我们还发现半胱氨酸C7和C106在稳定二聚体从而提高M-PMV PR的蛋白水解性方面起着至关重要的作用。这与半胱氨酸残基的可逆氧化修饰在调节细胞质中组装的M-PMV衣壳成熟中的作用是一致的。(C)2003爱思唯尔有限公司。保留所有权利。
The assembly of Mason-Pfizer monkey virus Gag polyproteins into immature capsids and their cleavage by the encoded protease are temporally and spatially separated processes, making the virus a particularly useful model for investigation of protease activation. Here we present a high resolution NMR structure of a fully folded monomer of a 12 kDa M-PMV protease (wt 12 PR) and of a Cys7Ala/Asp26Asn/Cys106Ala. mutant (12 PRD26N/C7A/C106A). The overall structures of both wt 12 PR and 12 PRD26N/C7A/C106A follow the conservative structural motif of other retroviral proteases. The most prominent difference from the canonical fold of retroviral proteases is the absence of the interfacial beta-sheet, which leads to the loss of the principal force stabilizing the dimer of M-PMV PR. The monomer-dimer equilibrium can be shifted in favor of the dimer by adding a substrate or an inhibitor, partially compensating for the missing role of the beta-sheet. We also show that cysteines C7 and C106 play a crucial role in stabilizing the dimer and consequently increasing the proteolytic activity of M-PMV PR. This is consistent with the role of reversible oxidative modification of the cysteine residues in the regulation of the maturation of assembled M-PMV capsids in the cytoplasm. (C) 2003 Elsevier Ltd. All rights reserved.