SELF-CLEAVAGE OF PLUS AND MINUS RNAS OF A VIRUSOID AND A STRUCTURAL MODEL FOR THE ACTIVE-SITES
SELF-CLEAVAGE OF PLUS AND MINUS RNAS OF A VIRUSOID AND A STRUCTURAL MODEL FOR THE ACTIVE-SITES
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DOI：
10.1016/0092-8674(87)90562-9
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发表时间：
1987-04-24
期刊：
影响因子：
64.5
通讯作者：
SYMONS, RH
中科院分区：
文献类型：
--
作者：
FORSTER, AC;SYMONS, RH
类病毒是依赖于植物病毒进行复制和降解的环状单链RNA。类病毒复制似乎涉及比单位长度长的正和负RNA，表明单位长度正RNA是由特异性切割反应产生的。在这里，我们在体外合成了来自卢塞恩瞬时条纹病毒的324个核苷酸的类病毒的正负部分长度的RNA。两种RNA在镁离子存在下在独特位点自切割以产生5“羟基和2”，3“环状磷酸二酯末端。天然结构以外的构象是裂解所必需的。这些和其他植物病原性RNA的活性位点提出了具有相当大的序列同源性的类似二级结构。我们的研究结果与某些滚环复制模型一致。
Virusoids are circular single-stranded RNAs dependent on plant viruses for replication and encapsidation. Virusoid replication appears to involve longer-than-unit-length plus and minus RNAs, indicating that unit-length plus RNA is generated by specific cleavage reactions. Here, we synthesize plus and minus partial-length RNAs of the 324-nucleotide virusoid from lucerne transient streak virus in vitro. Both RNAs self-cleave at a unique site in the presence of magnesium ions to give 5'' hydroxyl and 2'',3'' cyclic phosphodiester termini. Conformations other than the native structures are necessary for cleavage. Similar secondary structures with considerable sequence homology are proposed for the active sites of these and other plant pathogenic RNAs. Our results are consistent with certain rolling-circle replication models.