van den Elzen P J, Maat J, Walters H H, Veltkamp E, Nijkamp H J
Nucleic Acids Res. 1982 Mar 25;10(6):1913-28. doi: 10.1093/nar/10.6.1913.
Treatment of cells, harbouring the bacteriocinogenic plasmic Clo DF13 with mitomycin-C, which induces the cellular SOS response, results in a significantly increased transcription of the operon encoding the bacteriocin cloacin DF13, the immunity protein and the lysis protein H. The nucleotide sequences of the promoter regions and N-terminal parts of the bacteriocin genes of Clo DF13, Col E1 and the pMB1 derivative pBR324 have been determined. A comparison of these sequences with those of corresponding regions of the lexA, recA and uvrB genes revealed that the promoter regions of the bacteriocin genes studied contain binding sites for the lexA protein, which is the repressor of the E. coli DNA-repair system. Using both, a thermosensitive lexA host strain and a host with pACYC184 into which the lexA gene had been cloned, we were able to demonstrate, that in vivo the lexA protein is involved in the regulation of bacteriocin synthesis. From the data presented, we conclude that bacteriocin synthesis is controlled at least by the lexA repressor. It has been reported that also catabolite repression might play an essential role in the control of bacteriocin synthesis. Computer analysis of the DNA sequence data indicated that the promoter regions of both, the cloacin DF13 and colicin E1 genes contain potential binding sites for the cyclic AMP-cyclic AMP Receptor Protein complex.
用丝裂霉素-C处理携带产细菌素质粒Clo DF13的细胞，丝裂霉素-C可诱导细胞的SOS反应，结果导致编码细菌素cloacin DF13、免疫蛋白和裂解蛋白H的操纵子转录显著增加。已确定了Clo DF13、Col E1和pMB1衍生物pBR324的细菌素基因启动子区域和N端部分的核苷酸序列。将这些序列与lexA、recA和uvrB基因相应区域的序列进行比较，发现所研究的细菌素基因启动子区域含有lexA蛋白的结合位点，lexA蛋白是大肠杆菌DNA修复系统的阻遏物。利用热敏lexA宿主菌株和携带已克隆lexA基因的pACYC184的宿主，我们能够证明，在体内lexA蛋白参与细菌素合成的调控。根据所提供的数据，我们得出结论，细菌素合成至少受lexA阻遏物控制。据报道，分解代谢物阻遏在细菌素合成的控制中也可能起重要作用。对DNA序列数据的计算机分析表明，cloacin DF13和大肠杆菌素E1基因的启动子区域都含有环腺苷酸-环腺苷酸受体蛋白复合物的潜在结合位点。
