Proteins expressed by the bacterial cold shock genes are highly conserved at sequence level and perform various biological functions in both the cold-stressed and normal cells. To study the effects of various agents on the cold shock genes of Staphylococcus aureus, we have cloned the upstream region of cspC from S. aureus Newman and found that the above region possesses appreciable promoter (P(c)) activity even at 37 degrees C. A reporter S. aureus strain CHANDA2, constructed by inserting the P(c)-lacZ transcriptional fusion into S. aureus RN4220 genome, was found to express very low level of beta-galactosidase after cold shock, indicating that low temperature induces P(c) very weakly. Interestingly, transcription from P(c ) was induced very strongly by several antibiotics, hydrogen peroxide and arsenate salt. Cold shock proteins expressed by S. aureus are highly identical at sequence level and bear single-strand nucleic acid binding motifs. A 16 nt downstream box and a 13 nt upstream box were identified at the downstream of initiation codon and at the upstream of ribosome binding site of csp transcripts. Their roles in S. aureus cold shock gene expression have been discussed elaborately.
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