The Primary Study On The Regulation Mechanism Of The E.coli Cold Shock Protein A Promoter Region

Both prokaryotes and eukaryotes exhibit a cold shock response upon an abrupttemperature downshift. About 26-27 cold-shock proteins are synthesized to overcomethe deleterious effects of low temperature stress. CspA, the major cold-shock protein ofEscherichia coli, has recently been studied with respect to its structure, function andregulation at the level of transcription, translation and mRNA stability, especially thefunction of AT and DB region of its promoter.In this paper, plasmid pET-28a(+)was used for construction of three lowtemperature expression. ZsGreen was fused into the pET-28a(+)as the report gene.Wild cspA promoter, DB deletion promoter, DB and AT deletion promoter substitute theT7 promoter of the pET-28a(+). In order to explore the mechanism of the cspA,RT-PCR,SDS-PSGE and fluorescence spectrophotometry detection have been appliedto contrast and analyze the transcription and translation of the three expression carrier.The results shows that in 16℃, DB functions as the translation enhancer, and thedeletion of DB can make the stability of the cspA mRNAmuch stronger. AT has notingto do with the regulation of the cspA transcription. In addition, the activity of therecombinant protein ZsGreen is higher when expressed in low temperature than in hightemperature.