Berkhout B, Essink B B, Schoneveld I
Department of Virology, University of Amsterdam, The Netherlands.
FASEB J. 1993 Jan;7(1):181-7. doi: 10.1096/fasebj.7.1.8422965.
Retroviral particles contain a dimeric genome consisting of two full-length, noncovalently linked RNA molecules. Linkage of the two genomes is thought to be critical for a productive reverse transcription reaction and may increase genetic recombination rates. The molecular nature of the dimer linkage structure (DLS) is poorly understood. It was recently shown that in vitro synthesized retroviral transcripts can dimerize in the absence of protein factors. We studied in vitro dimerization of human immunodeficiency virus type 2 (HIV-2) RNA. Specific dimerization of HIV-2 RNAs was observed upon incubation at 37 degrees C in high-salt buffer. Previously, physical and biochemical studies have mapped dimer linkage structures in retroviral leader RNA close to the gag open reading frame. In this study, we found efficient dimerization of HIV-2 RNAs containing only the 5' terminal 255 nucleotides of the leader RNA. Therefore, it seems likely that multiple dimerization signals are present in retroviral leader RNA. The implications for genome dimerization and genome packaging are discussed.
逆转录病毒颗粒含有一个二聚体基因组，该基因组由两个全长、非共价连接的RNA分子组成。两个基因组的连接被认为对有效的逆转录反应至关重要，并且可能会提高基因重组率。二聚体连接结构（DLS）的分子性质目前还了解甚少。最近有研究表明，体外合成的逆转录病毒转录本在没有蛋白质因子的情况下也能二聚化。我们对2型人类免疫缺陷病毒（HIV-2）RNA的体外二聚化进行了研究。在37摄氏度的高盐缓冲液中孵育时，观察到HIV-2 RNA发生了特异性二聚化。此前，物理和生化研究已将逆转录病毒前导RNA中的二聚体连接结构定位在靠近gag开放阅读框的位置。在本研究中，我们发现仅包含前导RNA 5'末端255个核苷酸的HIV-2 RNA能高效二聚化。因此，逆转录病毒前导RNA中似乎可能存在多个二聚化信号。本文还讨论了其对基因组二聚化和基因组包装的影响。
