Marquet R, Paillart J C, Skripkin E, Ehresmann C, Ehresmann B
Unité Propre de Recherche 9002, Centre National de la Recherche Scientifique, Strasbourg, France.
Nucleic Acids Res. 1994 Jan 25;22(2):145-51. doi: 10.1093/nar/22.2.145.
The retroviral genome consists of two homologous RNA molecules associated close to their 5' ends. We studied the spontaneous dimerization of four HIV-1 RNA fragments (RNAs 1-707, 1-615, 311-612, and 311-415) containing the previously defined dimerization domain, and a RNA fragment (RNA 1-311) corresponding to the upstream sequences. Significant dimerization of all RNAs is observed on agarose gels when magnesium is included in the electrophoresis buffer. In contrast to dimerization of RNAs 311-612 and 311-415, dimerization of RNAs 1-707, 1-615 and 1-311 strongly depends on the size of the monovalent cation present in the incubation buffer. Also, dimerization of RNAs 1-707, 1-615, and 1-311 is 10 times faster than that of RNAs 311-612 and 311-415. The dimers formed by the latter RNAs are substantially more stable than that of RNA 1-615, while RNA 1-311 dimer is 5-7 degrees C less stable than RNA 1-615 dimer. These results indicate that dimerization of HIV-1 genomic RNA involves elements located upstream of the splice donor site (position 305), i.e. outside of the previously defined dimerization domain.
逆转录病毒基因组由两个同源RNA分子组成，它们在靠近5'端处紧密相连。我们研究了四个含有先前定义的二聚化结构域的HIV-1 RNA片段（RNA 1-707、1-615、311-612和311-415）以及一个对应于上游序列的RNA片段（RNA 1-311）的自发二聚化。当在电泳缓冲液中加入镁时，在琼脂糖凝胶上观察到所有RNA都有显著的二聚化现象。与RNA 311-612和311-415的二聚化不同，RNA 1-707、1-615和1-311的二聚化强烈依赖于孵育缓冲液中存在的单价阳离子的大小。此外，RNA 1-707、1-615和1-311的二聚化速度比RNA 311-612和311-415快10倍。后一种RNA形成的二聚体比RNA 1-615的二聚体稳定得多，而RNA 1-311二聚体比RNA 1-615二聚体的稳定性低5-7摄氏度。这些结果表明，HIV-1基因组RNA的二聚化涉及剪接供体位点（位置305）上游的元件，即在先前定义的二聚化结构域之外。
