Sutcliffe J G, Shinnick T M, Verma I M, Lerner R A
Proc Natl Acad Sci U S A. 1980 Jun;77(6):3302-6. doi: 10.1073/pnas.77.6.3302.
We have determined the sequence of a cloned DNA fragment 1108 base pairs long which corresponds to the 3' end of the Moloney murine leukemia provirus. The clone was obtained as the primary product of reverse transcription and begins with the Moloney "strong stop" sequence, then extends towards the 5' end of the provirus. Our sequence: (i) proves that reverse transcriptase switches templates during minus strand synthesis; (ii) defines the limits of the 515-base-pair repeats which occupy both ends of the integrated provirus; (iii) shows that the structure of the proviral repeats has strong analogy to bacterial insertion sequences, indicating that the Moloney provirus is a transposon; (iv) identifies the putative promotor for genomic transcription within these repeats; (v) shows that the presumed origin of second strand synthesis, which lies just outside the 3' repeat, has tertiary structure analogous to single-stranded bacteriophage origins of replication; (vi) solves the amino acid sequence of most of pI5E, the carboxy-terminal product of the env gene; (vii) allows detailed mapping of the mink cell focus-forming virus substitution locus in a central location within the gp70 region of the env gene; and (viii) identifies a long open translation frame to the right of the env gene (R gene) which could be involved in leukemogenesis.
我们已经确定了一个长度为1108个碱基对的克隆DNA片段的序列，该片段对应于莫洛尼氏鼠白血病前病毒的3'末端。该克隆是作为逆转录的主要产物获得的，起始于莫洛尼氏“强终止”序列，然后朝着前病毒的5'末端延伸。我们的序列：（i）证明逆转录酶在负链合成过程中会转换模板；（ii）确定了占据整合前病毒两端的515个碱基对重复序列的界限；（iii）表明前病毒重复序列的结构与细菌插入序列有很强的相似性，这表明莫洛尼氏前病毒是一种转座子；（iv）在这些重复序列中确定了基因组转录的推定启动子；（v）表明位于3'重复序列外侧的第二链合成的假定起始点具有类似于单链噬菌体复制起始点的三级结构；（vi）解析了env基因的羧基末端产物p15E大部分的氨基酸序列；（vii）允许在env基因的gp70区域中心位置对水貂细胞集落形成病毒替代位点进行详细定位；以及（viii）在env基因（R基因）右侧鉴定出一个可能参与白血病发生的长开放阅读框。
