Keene J D, Chien I M, Lazzarini R A
Proc Natl Acad Sci U S A. 1981 Apr;78(4):2090-4. doi: 10.1073/pnas.78.4.2090.
The RNA of a unique long defective interfering particle (DI-LT2) derived from the heat-resistant strain of vesicular stomatitis virus (VSV) contains 70 nucleotides at its 3' end that are complementary to the 5' end of the VSV RNA. Following this region of terminal complementarity, there is a precise copy of the 3' end of the nondefective VSV RNA. The sequence homology between the DI-LT2 RNA and the 3' end of VSV RNA extends for at least 60 bases and probably for most of the length of the DI-LT2 RNA. The DI-LT2 particle is capable of transcription in vitro but produces only a short RNA [defective interfering (DI) particle product], which is encoded by the extreme 3' terminus of the DI RNA. Neither leader RNA nor capped VSV mRNAs are synthesized by DI-LT2, although competent templates for these are present. These data suggest that the 3'-terminal initiation is a prerequisite of the production of competent transcripts and that the sequence coding for leader RNA is not, by itself, sufficient for initiation. We propose a model for the origin of this DI particle, involving specific termination and resumption of replication, which is similar to that described previously for another class of DI particle RNAs.
源自水疱性口炎病毒（VSV）耐热株的一种独特的长缺陷干扰颗粒（DI-LT2）的RNA，其3'端含有70个核苷酸，与VSV RNA的5'端互补。在这个末端互补区域之后，是无缺陷VSV RNA 3'端的精确拷贝。DI-LT2 RNA与VSV RNA 3'端之间的序列同源性至少延伸60个碱基，可能延伸至DI-LT2 RNA的大部分长度。DI-LT2颗粒能够在体外转录，但只产生一种短RNA [缺陷干扰（DI）颗粒产物]，它由DI RNA的最末端3'端编码。DI-LT2既不合成前导RNA，也不合成加帽的VSV mRNA，尽管存在这些的有效模板。这些数据表明，3'端起始是产生有效转录本的先决条件，并且编码前导RNA的序列本身不足以起始。我们提出了一个关于这种DI颗粒起源的模型，涉及特定的复制终止和重新起始，这与之前描述的另一类DI颗粒RNA的情况类似。
