Multiple regions of Harvey sarcoma virus RNA can dimerize in vitro
Multiple regions of Harvey sarcoma virus RNA can dimerize in vitro
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DOI：
10.1128/jvi.69.4.2486-2490.1995
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发表时间：
1995-04
影响因子：
5.4
通讯作者：
Y. Feng;W. Fu;A. Winter;J. G. Levin;A. Rein
中科院分区：
文献类型：
--
作者：
Y. Feng;W. Fu;A. Winter;J. G. Levin;A. Rein
逆转录病毒含有二聚体 RNA，由两个相同的正链基因组 RNA 分子组成。两个单体之间的连接结构尚不清楚，但据信它们在 5' 端附近连接。 Darlix 和同事报道逆转录病毒 RNA 序列的转录物可以在体外自发二聚化（参见例如 E. Bieth、C. Gabus 和 J. L. Darlix, Nucleic Acids Res. 18:119-127, 1990）。作为鉴定可能参与连接的序列的一种方法，我们绘制了源自可在体外二聚化的哈维肉瘤病毒(HaSV) RNA 5'378碱基的序列。我们发现至少三个不同的区域，由核苷酸37至229、205至272和271至378组成，可以形成这些二聚体。其中两个区域含有核苷酸 205 至 226；计算机分析表明该区域可以形成茎环，环中具有反向重复序列。我们认为这种假设的结构参与了这两个转录物的二聚体形成。我们还将这些二聚体的热稳定性与 HaSV 病毒 RNA 的热稳定性进行了比较。核苷酸37至229和205至272的二聚体均表现出接近病毒RNA的解链温度，而核苷酸271至378的二聚体相当不稳定。我们还发现，在 37 摄氏度下形成的核苷酸 37 至 378 二聚体的热稳定性低于在 55 摄氏度下形成的相同 RNA 的二聚体。来自所有这些区域的碱基似乎有可能参与病毒 RNA 中存在的二聚体连接。
Retroviruses contain a dimeric RNA consisting of two identical molecules of plus-strand genomic RNA. The structure of the linkage between the two monomers is not known, but they are believed to be joined near their 5' ends. Darlix and coworkers have reported that transcripts of retroviral RNA sequences can dimerize spontaneously in vitro (see, for example, E. Bieth, C. Gabus, and J. L. Darlix, Nucleic Acids Res. 18:119-127, 1990). As one approach to identification of sequences which might participate in the linkage, we have mapped sequences derived from the 5' 378 bases of Harvey sarcoma virus (HaSV) RNA which can dimerize in vitro. We found that at least three distinct regions, consisting of nucleotides 37 to 229, 205 to 272, and 271 to 378, can form these dimers. Two of these regions contain nucleotides 205 to 226; computer analysis suggests that this region can form a stem-loop with an inverted repeat in the loop. We propose that this hypothetical structure is involved in dimer formation by these two transcripts. We also compared the thermal stabilities of each of these dimers with that of HaSV viral RNA. Dimers of nucleotides 37 to 229 and 205 to 272 both exhibited melting temperatures near that of viral RNA, while dimers of nucleotides 271 to 378 are quite unstable. We also found that dimers of nucleotides 37 to 378 formed at 37 degrees C are less thermostable than dimers of the same RNA formed at 55 degrees C. It seems possible that bases from all of these regions participate in the dimer linkage present in viral RNA.