Ringuette M J, Spencer J H
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
Biochim Biophys Acta. 1994 Aug 2;1218(3):331-8. doi: 10.1016/0167-4781(94)90185-6.
Analysis of in vitro run-off transcripts synthesized by Escherichia coli RNA polymerase holoenzyme on linearized bacteriophage S13 DNA templates revealed five major transcription initiation sites. The sites, located at positions 45, 982, 1823 (1827), 4876 and 5211, are each within the boundaries of promoters or putative promoters previously mapped by footprinting and RNA polymerase binding analyses. They correspond to initiations at promoters upstream of the A, B, and D genes, and at a medium-affinity and a high-affinity RNA polymerase binding site P5211, respectively. Sequence analysis of the 5'-ends of two transcripts confirmed their initiation with pppA at nt 982 and nt 5211, the B gene and high-affinity binding site P5211, respectively. Some of the transcripts initiated at nt 4876 and nt 5211 terminated at nt 64, providing direct evidence of the functionality of a p-independent termination site at nt 64.
对大肠杆菌RNA聚合酶全酶在线性化噬菌体S13 DNA模板上合成的体外延伸转录本的分析揭示了五个主要转录起始位点。这些位点位于45、982、1823（1827）、4876和5211位，每个位点都在先前通过足迹法和RNA聚合酶结合分析绘制的启动子或推定启动子的边界内。它们分别对应于A、B和D基因上游启动子处的起始，以及中等亲和力和高亲和力RNA聚合酶结合位点P5211处的起始。对两个转录本5'端的序列分析证实，它们分别在982位核苷酸和5211位核苷酸处起始于pppA，分别为B基因和高亲和力结合位点P5211。一些在4876位核苷酸和5211位核苷酸处起始的转录本在64位核苷酸处终止，这为64位核苷酸处存在一个不依赖ρ因子的终止位点的功能提供了直接证据。
