Thompson T L, Centola M B, Deonier R C
Department of Biological Sciences, University of Southern California, Los Angeles 90089-1340.
J Mol Biol. 1989 Jun 5;207(3):505-12. doi: 10.1016/0022-2836(89)90460-9.
The oriT locus of the Escherichia coli K12 F plasmid contains a site at which one of the DNA strands is cleaved as a prelude to conjugal transmission to recipient bacteria. We have remapped this site biochemically by using oriT-containing plasmids that were purified from bacteria expressing the F transfer (tra) functions. The strand interruption was found on the transferred strand 137 base-pairs clockwise of the center of the BglII site at 66.7 on the F map. This location is consistent with the locations anticipated from studies of delta traF' plasmids, but it differs from previous results by other investigators. The strand interruption produced a 3'-OH, but the nature of the 5' terminus of the strand on the other side of the nick was not determined. Some DNA sequence motifs in the vicinity of the oriT nick site of F resemble the chromosomal site involved in formation of delta traF'purE plasmids.
大肠杆菌K12 F质粒的oriT位点包含一个DNA链被切割的位点，这是向受体细菌进行接合转移的前奏。我们通过使用从表达F转移（tra）功能的细菌中纯化的含oriT质粒，对该位点进行了生化重定位。发现链中断位于F图谱上66.7处BglII位点中心顺时针137个碱基对的转移链上。该位置与对δtraF'质粒研究预期的位置一致，但与其他研究者先前的结果不同。链中断产生了一个3'-OH，但切口另一侧链的5'末端性质未确定。F的oriT切口位点附近的一些DNA序列基序类似于参与形成δtraF'purE质粒的染色体位点。
