The influence of 3TC resistance mutation M184I on the fidelity and error specificity of human immunodeficiency virus type 1 reverse transcriptase
The influence of 3TC resistance mutation M184I on the fidelity and error specificity of human immunodeficiency virus type 1 reverse transcriptase
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DOI：
10.1093/nar/26.12.3066
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发表时间：
1998-06-15
影响因子：
14.9
通讯作者：
Prasad, VR
中科院分区：
文献类型：
--
作者：
Rezende, LF;Drosopoulos, WC;Prasad, VR
针对人类免疫缺陷病毒1型（HIV-1）的治疗的常见靶点是病毒逆转录酶（RT）。用广泛使用的核苷类似物（-）-2 ′，3 ′-脱氧-3 ′-硫代胞苷（3 TC）治疗导致RT的YMDD基序内残基M184处产生赋予抗性的突变。首先，具有M184 I取代的HIV变体短暂出现，随后是含有M184 V取代的病毒，其持续存在并成为治疗期间的主要变体。在与双链DNA复合的HIV-1 RT的三维晶体结构中，M184残基位于引物末端附近，靠近引入的dNTP底物。最近的研究表明，3 TC抗性突变，包括M184 I，增加了核苷酸插入和错配延伸保真度。因此，我们通过基于M13的正向突变试验来检查M184 I突变对HIV-1 RT的总体聚合酶保真度的影响。我们发现HIV-1 RT的M184 I变体的总体错误率为1.7 × 10 - 5个核苷酸。这表示保真度比野生型HIV-1（Hxb 2）RT（7.0 x 10（-5）pea核苷酸）增加了4倍，比M184 V变体（4.3 x 10（-5）每个核苷酸）增加了2.5倍。在使用正向试验研究的核苷类似物耐药突变中，M184 I变体显示出迄今为止观察到的保真度的最大增加。有趣的是，M184 I变体RT显示出显著改变的错误特异性，无论是在特定位点的错误率方面，还是在整个靶标中取代与移码突变的总体比率方面。
A common target for therapies against human immunodeficiency virus type 1 (HIV-1) is the viral reverse transcriptase (RT), Treatment with the widely used nucleoside analog (-)-2',3'-deoxy-3'-thiacytidine (3TC) leads to the development of resistance-conferring mutations at residue M184 within the YMDD motif of RT. First, variants of HIV with the M184I substitution appear transiently, followed by viruses containing the M184V substitution, which persist and become the dominant variant for the duration of therapy, in the three-dimensional crystal structure of HIV-1 RT complexed with double-stranded DNA, the M184 residue lies in the vicinity of the primer terminus, near the incoming dNTP substrate. Recent studies have shown that 3TC resistance mutations, Including M184I, increase the nucleotide insertion and mispair extension fidelity, Therefore, we have examined the effects of the M184I mutation on the overall polymerase fidelity of HIV-1 RT via an M13-based forward mutation assay. We found the overall error rate of the M184I variant of HIV-1 RT to be 1.7 x 10(-5) per nucleotide. This represents a 4-fold increase in fidelity over wild-type HIV-1(Hxb2) RT (7.0 x 10(-5) pea nucleotide) and a 2.5-fold increase in fidelity over the M184V variant (4.3 x 10(-5) per nucleotide). Of the nucleoside analog resistance mutations studied using the forward assay, the M184I variant has shown the greatest increase in fidelity observed to date. Interestingly, the M184I variant RT displays significantly altered error specificity, both in terms of error rate at specific sites and in the overall ratio of substitution to frameshift mutations in the entire target.