Rauch Peter J G, Palmen Ronald, Burds Aurora A, Gregg-Jolly Leslie A, van der Zee J Rob, Hellingwerf Klaas J
Department of Microbiology, E. C. Slater Institute, BioCentrum Amsterdam, Nieuwe Achtergracht 127, 1018 TV Amsterdam, The Netherlands.
Department of Biology, Grinell College, Grinell, IA 50112, USA.
Microbiology (Reading). 1996 Apr;142 ( Pt 4):1025-1032. doi: 10.1099/00221287-142-4-1025.
Using the lacZ operon fusion technique, the transcriptional control of the Acinetobacter calcoaceticus recA gene was studied. A low (approximately twofold) inductive capacity was observed for compounds that damage DNA and/or inhibit DNA replication, e.g. methyl methanesulfonate, mitomycin C, UV light and nalidixic acid. Induction of the recA gene by DNA damage was independent of functional RecA. The presence of the recA promoter region on a multicopy plasmid had the same effect on recA transcription as the presence of DNA-damaging agents. Thus, recA expression in A. calcoaceticus appears to be regulated in a novel fashion, possibly involving a non-LexA-like repressor. Regulation of the recA gene in A. calcoaceticus appears not to be part of a regulon responsible for competence for natural transformation: in cells exhibiting extremely low transformation frequencies, the level of transcription of the recA gene was found to be comparable to the level found in cells in the state of maximal competence.
利用lacZ操纵子融合技术，对醋酸钙不动杆菌recA基因的转录调控进行了研究。对于那些能损伤DNA和/或抑制DNA复制的化合物，如甲基磺酸甲酯、丝裂霉素C、紫外线和萘啶酸，观察到了较低（约两倍）的诱导能力。DNA损伤对recA基因的诱导与功能性RecA无关。多拷贝质粒上recA启动子区域的存在对recA转录的影响与DNA损伤剂的存在相同。因此，醋酸钙不动杆菌中recA的表达似乎以一种新的方式受到调控，可能涉及一种非LexA样的阻遏物。醋酸钙不动杆菌中recA基因的调控似乎不是负责自然转化能力的调节子的一部分：在转化频率极低的细胞中，发现recA基因的转录水平与处于最大转化能力状态的细胞中的水平相当。
