Identification and transcriptional analysis of a cold shock-inducible gene, cspA, in Streptomyces coelicolor A3(2).

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.