Kormanec J, Sevcíková B
Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
Mol Gen Genet. 2000 Oct;264(3):251-6. doi: 10.1007/s004380000298.
Using the method for identification of promoters recognized by the sporulation-specific sigma factor sigmaF, we identified a promoter, cspAp, in Streptomyces coelicolor, which showed similarity to the consensus sequence of Bacillus subtilis promoters recognized by the general stress-response sigma factor sigmaB. cspAp directs expression of the cspA gene, which shows sequence similarity to members of the family of major cold shock proteins (CspA) from bacterial species. S1-nuclease mapping using RNA prepared from Escherichia coli containing a two-plasmid system, and from Streptomyces coelicolor at various developmental stages, identified identical transcription start points in both species, corresponding to cspAp. However, the promoter was also active in a S. coelicolor sigF mutant. Transcriptional studies indicated that cspA is transcribed as a monocistronic mRNA. The level of cspA mRNA remains almost constant in all developmental stages, is dramatically increased after cold shock, and decreased after heat shock. Disruption of the S. coelicolor cspA gene did not affect growth or differentiation at 11 degrees C or 30 degrees C.
利用芽孢形成特异性σ因子σF识别启动子的方法，我们在天蓝色链霉菌中鉴定出一个启动子cspAp，它与一般应激反应σ因子σB识别的枯草芽孢杆菌启动子的共有序列相似。cspAp指导cspA基因的表达，该基因与来自细菌物种的主要冷休克蛋白（CspA）家族成员具有序列相似性。使用从含有双质粒系统的大肠杆菌以及处于不同发育阶段的天蓝色链霉菌制备的RNA进行S1核酸酶作图，确定了两个物种中相同的转录起始点，对应于cspAp。然而，该启动子在天蓝色链霉菌sigF突变体中也具有活性。转录研究表明，cspA作为单顺反子mRNA进行转录。cspA mRNA的水平在所有发育阶段几乎保持恒定，冷休克后显著增加，热休克后降低。天蓝色链霉菌cspA基因的破坏在11℃或30℃下不影响生长或分化。
