Kirby T W, Hindenach B R, Greene R C
J Bacteriol. 1986 Mar;165(3):671-7. doi: 10.1128/jb.165.3.671-677.1986.
We subcloned DNA of the intercistronic region between the divergently transcribed metJ and metB genes of Escherichia coli into the transcription-fusion vector pK01 and localized the metJ promoters by deletion analysis. The plasmid-borne promoters of both genes were repressed by chromosomal metJ. In addition, S1 nuclease mapping of chromosomally derived mRNA from a derepressed strain revealed the start sites of transcription for metBL, metF, and metJ. The metBL and metF genes each had a single transcript which was repressed by metJ, while the metJ gene had three transcripts, of which the first was strongly repressed by metJ, the second was less strongly repressed, and the third was not repressed.
我们将大肠杆菌中反向转录的metJ和metB基因间顺反子间区域的DNA亚克隆至转录融合载体pK01中，并通过缺失分析定位了metJ启动子。两个基因的质粒携带型启动子均受染色体metJ的抑制。此外，对去阻遏菌株中染色体来源的mRNA进行S1核酸酶作图，揭示了metBL、metF和metJ的转录起始位点。metBL和metF基因各有一个受metJ抑制的单一转录本，而metJ基因有三个转录本，其中第一个受metJ强烈抑制，第二个抑制较弱，第三个不受抑制。
