Molecular mimicry of human tRNALys anti-codon domain by HIV-1 RNA genome facilitates tRNA primer annealing
Molecular mimicry of human tRNALys anti-codon domain by HIV-1 RNA genome facilitates tRNA primer annealing
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DOI：
10.1261/rna.036681.112
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发表时间：
2013-02-01
期刊：
影响因子：
4.5
通讯作者：
Musier-Forsyth, Karin
中科院分区：
文献类型：
--
作者：
Jones, Christopher P.;Saadatmand, Jenan;Musier-Forsyth, Karin
在人类免疫缺陷病毒1型（HIV-1）中启动逆转录的引物是tRNA（Lys 3）。宿主细胞tRNA（Lys）通过主要tRNA（Lys）结合蛋白、人赖氨酰-tRNA合成酶（hLysRS）和病毒蛋白Gag和GagPol之间的特异性相互作用被选择性地包装到HIV-1中。tRNA引物退火到病毒RNA中的互补引物结合位点（PBS）上是由Gag的核衣壳结构域介导的。tRNA（Lys 3）靶向PBS并在退火之前从hLysRS释放的机制是未知的。在这里，我们表明，hLysRS特异性结合到一个tRNA反密码子样元件（TLE）在HIV-1基因组中，它模仿的反密码子环的tRNA（赖氨酸），并位于接近PBS。TLE内的富U序列的突变减弱了体外hLysRS的结合，并减少了病毒体中退火tRNA（Lys 3）的量。因此，LysRS特异性结合TLE，TLE是病毒RNA中更大的LysRS结合结构域的一部分，其包括Psi包装信号的元件。我们的研究结果表明，HIV-1使用tRNA（Lys）的反密码子的分子模拟来增加tRNA（Lys 3）与病毒RNA退火的效率。
The primer for initiating reverse transcription in human immunodeficiency virus type 1 (HIV-1) is tRNA(Lys3). Host cell tRNA(Lys) is selectively packaged into HIV-1 through a specific interaction between the major tRNA(Lys)-binding protein, human lysyl-tRNA synthetase (hLysRS), and the viral proteins Gag and GagPol. Annealing of the tRNA primer onto the complementary primer-binding site (PBS) in viral RNA is mediated by the nucleocapsid domain of Gag. The mechanism by which tRNA(Lys3) is targeted to the PBS and released from hLysRS prior to annealing is unknown. Here, we show that hLysRS specifically binds to a tRNA anti-codon-like element (TLE) in the HIV-1 genome, which mimics the anti-codon loop of tRNA(Lys) and is located proximal to the PBS. Mutation of the U-rich sequence within the TLE attenuates binding of hLysRS in vitro and reduces the amount of annealed tRNA(Lys3) in virions. Thus, LysRS binds specifically to the TLE, which is part of a larger LysRS binding domain in the viral RNA that includes elements of the Psi packaging signal. Our results suggest that HIV-1 uses molecular mimicry of the anti-codon of tRNA(Lys) to increase the efficiency of tRNA(Lys3) annealing to viral RNA.