Granston A E, Thompson D L, Friedman D I
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor 48109.
J Bacteriol. 1990 May;172(5):2336-42. doi: 10.1128/jb.172.5.2336-2342.1990.
The metY-nusA-infB operon of Escherichia coli encodes functions involved in both transcription and translation. Previous studies have identified a single promoter, P0, that directs transcription of the entire operon. We have identified a second promoter, P-1, that also is positioned to transcribe the complete operon. P-1 is located 50 base pairs upstream of and oriented in the same direction as P0. Sequences associated with P-1 have features suggestive of regulatory elements. P-1 differs from any previously described naturally occurring E. coli promoter by having -35 and -10 sequences that perfectly match the procaryotic promoter consensus hexamer sequences, although the spacing between the two elements is 1 base pair more than optimal. We demonstrate that P-1 is active in vivo.
大肠杆菌的metY-nusA-infB操纵子编码参与转录和翻译的功能。先前的研究已经鉴定出一个单一的启动子P0，它指导整个操纵子的转录。我们已经鉴定出第二个启动子P-1，它也定位为转录完整的操纵子。P-1位于P0上游50个碱基对处，且方向与P0相同。与P-1相关的序列具有提示调控元件的特征。P-1与任何先前描述的天然存在的大肠杆菌启动子不同，其-35和-10序列与原核启动子共有六聚体序列完美匹配，尽管这两个元件之间的间距比最佳间距多1个碱基对。我们证明P-1在体内是有活性的。
