An in vivo mutation from leucine to tryptophan at position 210 in human immunodeficiency virus type 1 reverse transcriptase contributes to high-level resistance to 3'-azido-3'-deoxythymidine
An in vivo mutation from leucine to tryptophan at position 210 in human immunodeficiency virus type 1 reverse transcriptase contributes to high-level resistance to 3'-azido-3'-deoxythymidine
复制标题
DOI：
10.1128/jvi.70.11.8010-8018.1996
复制
发表时间：
1996-11-01
影响因子：
5.4
通讯作者：
Deacon, NJ
中科院分区：
文献类型：
--
作者：
Hooker, DJ;Tachedjian, G;Deacon, NJ
对8例接受3 '-叠氮基-3'-脱氧胸苷（AZT）治疗的患者的26株人类免疫缺陷病毒（HIV-1）分离株的逆转录（RT）区进行测序，发现210位密码子从TTG（亮氨酸）突变为TGG（色氨酸），这仅与AZT耐药有关。突变Trp-210在20株AZT表型耐药菌株中的15株中观察到，比密码子67、70和219处的耐药相关突变更常见。在出现耐药相关突变Leu-41和Tyr-215之前从未观察到Trp-210，并且在来自一名患者的五个分离株的连续系列中，发现突变出现的顺序是Tyr-215，Leu-41，然后是Trp-210。Trp-210也与Leu-41、Asn-67、Arg-70和Tyr-215耐药基因型相关。为了确定Trp-210在AZT抗性中的作用，构建了在密码子41、67、70、210和215处具有各种RT突变组合的分子HIV-1克隆，并测试了对AZT的敏感性。在含有来自HXB 2-D或临床分离株的聚合酶基因的克隆中，单独的Trp-210并不增加AZT抗性，而与Leu-41和Tyr-215结合，Trp-210进入密码子41、67、70和215处突变的遗传背景中进一步增强抗性，从1.44 μ M的50%抑制浓度增加到8.41 μ M。HIV-1 RT的三级结构的分子建模揭示，Trp-210（在螺旋α F中）和Tyr-215（在链β 11 a中）的侧链之间的距离接近4埃（1埃= 0.1 nm），足够接近以导致这两个芳香族侧链之间的显著能量相互作用。总之，Trp-210通过在两种耐药基因型的背景下将耐药性增强至少三至六倍而显著促进HIV-1的表型AZT耐药性，并且其作用可能需要与位置215处的芳香族氨基酸相互作用。
Sequencing of the reverse transcription (RT) region of 26 human immunodeficiency virus type (HIV-1) isolates from eight patients treated with 3'-azido-3'-deoxythymidine (AZT) revealed a mutation at codon 210 from TTG (leucine) to TGG (tryptophan) exclusively in association with resistance to AZT. The mutation Trp-210 was observed in 15 of the 20 isolates phenotypically resistant to AZT, being more commonly observed than resistance-associated mutations at codons 67, 70, and 219. Trp-210 was never observed before the emergence of resistance-associated mutations Leu-41 and Tyr-215, and in a sequential series of five isolates from one patient the order of emergence of mutations was found to be Tyr-215, Leu-41, and then Trp-210. Trp-210 was also found in association with the Leu-41, Asn-67, Arg-70, and Tyr-215 resistance genotype. To define the role of Trp-210 in AZT resistance, molecular HIV-1 clones were constructed with various combinations of RT mutations at codons 41, 67, 70, 210, and 215 and tested for susceptibility to AZT. In clones with polymerase genes derived either from HXB2-D or clinical isolates, Trp-210 alone did not increase AZT resistance, whereas in conjunction with Leu-41 and Tyr-215, Trp-210 into the genetic context of mutations at codons 41, 67, 70, and 215 further enhanced resistance from a 50% inhibitory concentration of 1.44 mu M to 8.41 mu M. Molecular modeling of the tertiary structure of HIV-1 RT revealed that the distance between the side chains of Trp-210 (in helix alpha F) and Tyr-215 (in strand beta 11a) approximated 4 Angstrom (1 Angstrom = 0.1 nm), sufficiently close to result in significant energetic interaction between these two aromatic side chains. In conclusion, Trp-210 contributes significantly to phenotypic AZT resistance of HIV-1 by augmenting resistance at least three- to sixfold in the context of two resistant genotypes, and its effect may require an interaction with an aromatic amino acid at position 215.