IDENTIFICATION OF THE PROMOTER REGION OF THE ESCHERICHIA-COLI MAJOR COLD SHOCK GENE, CSPA

The major cold shock protein of Escherichia coli, CS7.4, is produced at a level of 13% of total protein synthesis upon a temperature shift from 37 to 10-degrees-C. The transcription of its gene (cspA) was found to be tightly regulated and induced only at low temperature. In addition, the cspA mRNA was extremely unstable at 37-degrees-C, so that CS7.4 production was hardly detected when the culture temperature was shifted from 15-degrees-C to 37-degrees-C. The transcription initiation site (+1) was identified. In vivo footprinting demonstrated that the region from bases -35 to -73 was protected from chemical modification, and gel mobility shift analysis showed that a cold-shocked cell extract contained a factor(s) specifically bound to the fragment containing the sequence between bases -63 and -92. This factor was synthesized de novo only at low temperature, and its synthesis was inhibited by chloramphenicol. Possible functions of this factor are discussed.