Structural basis for coevolution of a human immunodeficiency virus type 1 nucleocapsid-p1 cleavage site with a V82A drug-resistant mutation in viral protease
Structural basis for coevolution of a human immunodeficiency virus type 1 nucleocapsid-p1 cleavage site with a V82A drug-resistant mutation in viral protease
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DOI：
10.1128/jvi.78.22.12446-12454.2004
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发表时间：
2004-11-01
影响因子：
5.4
通讯作者：
Schiffer, CA
中科院分区：
文献类型：
--
作者：
Prabu-Jeyabalan, M;Nalivaika, EA;Schiffer, CA
人类免疫缺陷病毒（HIV）的成熟依赖于病毒蛋白酶对Gag和Pol多聚蛋白的加工，使这种酶成为抗HIV治疗的主要靶标。在蛋白酶底物中，核衣壳-p1（NC-p1）序列同源性最低，其切割是病毒成熟的速率决定步骤。在HIV-1蛋白酶的其他底物中，P1通常是疏水性或芳香性残基，P2通常是支链残基。然而，NC-p1在P1处含有Asn，在P2处含有Ala。响应于V82 A耐药蛋白酶突变，NC-p1的P2丙氨酸突变为缬氨酸（AP 2 V）。为了提供HIV-1蛋白酶与NC-p1切割位点结合的结构原理，我们解析了无活性（D25 N）WT和V82 A HIV-1蛋白酶与其各自的WT和AP 2 V突变体NC-p1底物复合的晶体结构。总的来说，WT NC-p1肽与HIV-1蛋白酶的结合不如AP 2 V突变体最佳，如存在较少的氢键和较少的货车范德华接触所示。AlaP 2不能完全填充P2口袋; PheP 1 '与Val 82发生货车德瓦尔斯相互作用，而V82 A蛋白酶突变则使这种相互作用丧失。这种损失由AP 2 V突变补偿，其将肽重新定向为与在其他底物-蛋白酶复合物中观察到的构象更相似的构象。因此，突变底物不仅更佳地结合突变蛋白酶，而且还揭示了P1'和P2底物位点之间的相互依赖性。这种结构上的相互依赖性是由底物与病毒蛋白酶的共同进化引起的。
Maturation of human immunodeficiency virus (HIV) depends on the processing of Gag and Pol polyproteins by the viral protease, making this enzyme a prime target for anti-HIV therapy. Among the protease substrates, the nucleocapsid-p1 (NC-p1) sequence is the least homologous, and its cleavage is the rate-determining step in viral maturation. In the other substrates of HIV-1 protease, P1 is usually either a hydrophobic or an aromatic residue, and P2 is usually a branched residue. NC-p1, however, contains Asn at PI and Ala at P2. In response to the V82A drug-resistant protease mutation, the P2 alanine of NC-p1 mutates to valine (AP2V). To provide a structural rationale for HIV-1 protease binding to the NC-p1 cleavage site, we solved the crystal structures of inactive (D25N) WT and V82A HIV-1 proteases in complex with their respective WT and AP2V mutant NC-p1 substrates. Overall, the WT NC-p1 peptide binds HIV-1 protease less optimally than the AP2V mutant, as indicated by the presence of fewer hydrogen bonds and fewer van der Waals contacts. AlaP2 does not fill the P2 pocket completely; PheP1' makes van der Waals interactions with Val82 that are lost with the V82A protease mutation. This loss is compensated by the AP2V mutation, which reorients the peptide to a conformation more similar to that observed in other substrate-protease complexes. Thus, the mutant substrate not only binds the mutant protease more optimally but also reveals the interdependency between the P1' and P2 substrate sites. This structural interdependency results from coevolution of the substrate with the viral protease.