CONTROL OF GENE-EXPRESSION IN THE TEMPERATE COLIPHAGE-186 .8. CONTROL OF LYSIS AND LYSOGENY BY A TRANSCRIPTIONAL SWITCH INVOLVING FACE-TO-FACE PROMOTERS
CONTROL OF GENE-EXPRESSION IN THE TEMPERATE COLIPHAGE-186 .8. CONTROL OF LYSIS AND LYSOGENY BY A TRANSCRIPTIONAL SWITCH INVOLVING FACE-TO-FACE PROMOTERS
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DOI：
10.1016/0022-2836(90)90144-b
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发表时间：
1990-07-05
影响因子：
5.6
通讯作者：
EGAN, JB
中科院分区：
文献类型：
--
作者：
DODD, IB;KALIONIS, B;EGAN, JB
温带大肠杆菌噬菌体186的溶原性和早期裂解操纵子转录分歧。这些体外转录物的5“末端的引物延伸作图显示，溶胞启动子pR和溶胞原启动子pL面对面排列，其转录物重叠60个碱基。我们研究了使用galK作为报告基因从pR和pL转录的控制。溶原性cI基因的产物强烈抑制pR转录，同时允许pL转录。裂解apl基因（以前的CP 75）的产物强烈抑制pL转录，而允许pR转录。因此，cI-pR-pL-apl区域起着转录开关的作用，决定转录是裂解性的还是溶原性的。此外，cI基因产物能够刺激pL，可能是通过减轻抑制pL转录所造成的收敛转录从PR。其他后果的面对面的启动子安排进行了讨论。
The lysogenic and early lytic operons of the temperate coliphage 186 are transcribed divergently. Primer extension mapping of the 5'' ends of these in vitro transcripts showed that the rightward lytic promoter, pR, and the leftward lysogenic promoter, pL, are arranged face-to-face with their transcripts overlapping by 60 bases. We examined the control of transcription from pR and pL using galK as a reporter gene. The product of the lysogenic cI gene strongly repressed pR transcription while allowing pL transcription. The product of the lytic apl gene (formerly CP75) strongly repressed pL transcription while allowing pR transcription. Thus, the cI-pR-pL-apl region functioned as a transcriptional switch, determining whether transcription was lytic or lysogenic. Also, the cI gene product was able to stimulate pL, possibly by alleviating an inhibition of pL transcription caused by convergent transcription from pR. Other consequences of the face-to-face promoter arrangement are discussed.