Zain B S, Dhar R, Weissman S M, Lebowitz P, Lewis A M
J Virol. 1973 May;11(5):682-93. doi: 10.1128/JVI.11.5.682-693.1973.
The DNA of simian virus 40 (SV40) was transcribed into RNA by Escherichia coli RNA polymerase at 18 to 24 C after synchronization of the initiation of RNA synthesis. After a brief synthetic period the RNA product contained relatively large amounts of sequences derived from a limited segment of SV40 DNA. The source for this pulse-labeled RNA was found to be a portion of the segment of SV40 DNA included within the nondefective adenovirus (Ad)-SV40 hybrid viruses, Ad2(+)ND(1) and Ad2(+)ND(3). After synthesis with [gamma-(32)P] ATP, Ad2(+)ND(1) and Ad2(+)ND(3) DNA transcripts contained an initial sequence missing from Ad2 transcripts. This sequence was identified as an initiation sequence for polymerase transcription of the SV40 DNA. Thus, there is a preferred site for initiation of in vitro transcription on the segment of SV40 DNA common to the nondefective Ad2(+)ND(1) and Ad2(+)ND(3) hybrid viruses.
在RNA合成起始同步化后,猿猴病毒40(SV40)的DNA在18至24摄氏度下被大肠杆菌RNA聚合酶转录为RNA。经过短暂的合成期后,RNA产物包含相对大量源自SV40 DNA有限片段的序列。发现这种脉冲标记RNA的来源是无缺陷腺病毒(Ad)-SV40杂交病毒Ad2(+)ND(1)和Ad2(+)ND(3)中包含的SV40 DNA片段的一部分。在用[γ-(32)P]ATP合成后,Ad2(+)ND(1)和Ad2(+)ND(3) DNA转录本包含Ad2转录本中缺失的初始序列。该序列被鉴定为SV40 DNA聚合酶转录的起始序列。因此,在无缺陷的Ad2(+)ND(1)和Ad2(+)ND(3)杂交病毒共有的SV40 DNA片段上存在体外转录起始的优选位点。