Marquet R, Baudin F, Gabus C, Darlix J L, Mougel M, Ehresmann C, Ehresmann B
Laboratoire de Biochimie, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France.
Nucleic Acids Res. 1991 May 11;19(9):2349-57. doi: 10.1093/nar/19.9.2349.
The retroviral genome consists of two identical RNA molecules joined close to their 5' ends by the dimer linkage structure. Recent findings indicated that retroviral RNA dimerization and encapsidation are probably related events during virion assembly. We studied the cation-induced dimerization of HIV-1 RNA and results indicate that all in vitro generated HIV-1 RNAs containing a 100 nucleotide domain downstream from the 5' splice site are able to dimerize. RNA dimerization depends on the concentration of RNA, mono- and multivalent cations, the size of the monovalent cation, temperature, and pH. Up to 75% of HIV-1 RNA is dimeric in the presence of spermidine. HIV-1 RNA dimer is fairly resistant to denaturing agents and unaffected by intercalating drugs. Antisense HIV-1 RNA does not dimerize but heterodimers can be formed between HIV-1 RNA and either MoMuLV or RSV RNA. Therefore retroviral RNA dimerization probably does not simply proceed through mechanisms involving Watson-Crick base-pairing. Neither adenine and cytosine protonation, nor quartets containing only guanines appear to determine the stability of the HIV-1 RNA dimer, while quartets involving both adenine(s) and guanine(s) could account for our results. A consensus sequence PuGGAPuA found in the putative dimerization-encapsidation region of all retroviral genomes examined may participate in the dimerization process.
逆转录病毒基因组由两个相同的RNA分子组成，它们通过二聚体连接结构在靠近其5'端处相连。最近的研究结果表明，逆转录病毒RNA二聚化和包装可能是病毒体组装过程中的相关事件。我们研究了阳离子诱导的HIV-1 RNA二聚化，结果表明，所有体外产生的、在5'剪接位点下游含有100个核苷酸结构域的HIV-1 RNA都能够二聚化。RNA二聚化取决于RNA的浓度、单价和多价阳离子、单价阳离子的大小、温度和pH值。在亚精胺存在的情况下，高达75%的HIV-1 RNA是二聚体。HIV-1 RNA二聚体对变性剂相当耐受，不受嵌入药物的影响。反义HIV-1 RNA不会二聚化，但HIV-1 RNA与莫洛尼鼠白血病病毒（MoMuLV）或劳斯肉瘤病毒（RSV）RNA之间可以形成异源二聚体。因此，逆转录病毒RNA二聚化可能并非简单地通过涉及沃森-克里克碱基配对的机制进行。腺嘌呤和胞嘧啶的质子化，以及仅含鸟嘌呤的四重体似乎都不能决定HIV-1 RNA二聚体的稳定性，而涉及腺嘌呤和鸟嘌呤的四重体可能可以解释我们的结果。在所有检测的逆转录病毒基因组的假定二聚化-包装区域中发现的共有序列PuGGAPuA可能参与了二聚化过程。
