Circularization of the HIV-1 genome facilitates strand transfer during reverse transcription
Circularization of the HIV-1 genome facilitates strand transfer during reverse transcription
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DOI：
10.1261/rna.2039610
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发表时间：
2010-06-01
期刊：
影响因子：
4.5
通讯作者：
Kjems, Jorgen
中科院分区：
文献类型：
--
作者：
Beerens, Nancy;Kjems, Jorgen
在逆转录病毒RNA基因组的逆转录过程中发生两个强制性DNA链转移。第一链转移涉及从位于病毒基因组各末端的5'至3'末端重复（R）区的跳跃。该过程依赖于从5' R区域合成的cDNA和3' R RNA之间的碱基配对。病毒RNA基因组的三级构象可通过将线性序列中相距9 kb的5' R和3' R序列并置来促进链转移。在这项研究中，通过突变分析绘制了参与HIV-1基因组5'和3'末端之间相互作用的RNA序列。这种相互作用似乎主要由病毒基因组3'末端和gag开放阅读框中的序列介导。3 ′ R序列的突变抑制了5 ′-3 ′相互作用，而5 ′ gag区的互补突变可恢复这种相互作用。此外，我们发现HIV-1基因组的环化不影响逆转录的起始，但在体外逆转录过程中刺激第一链转移，强调了相互作用的功能重要性。
Two obligatory DNA strand transfers take place during reverse transcription of a retroviral RNA genome. The first strand transfer involves a jump from the 5' to the 3' terminal repeat (R) region positioned at each end of the viral genome. The process depends on base pairing between the cDNA synthesized from the 5' R region and the 3' R RNA. The tertiary conformation of the viral RNA genome may facilitate strand transfer by juxtaposing the 5' R and 3' R sequences that are 9 kb apart in the linear sequence. In this study, RNA sequences involved in an interaction between the 5' and 3' ends of the HIV-1 genome were mapped by mutational analysis. This interaction appears to be mediated mainly by a sequence in the extreme 3' end of the viral genome and in the gag open reading frame. Mutation of 3' R sequences was found to inhibit the 5'-3' interaction, which could be restored by a complementary mutation in the 5' gag region. Furthermore, we find that circularization of the HIV-1 genome does not affect the initiation of reverse transcription, but stimulates the first strand transfer during reverse transcription in vitro, underscoring the functional importance of the interaction.