Negative regulation of IS2 transposition by the cyclic AMP (cAMP)-cAMP receptor protein complex.
Three sequences similar to that of the consensus binding sequence of the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex were found in the major IS2 promoter region. Experiments were performed to determine whether the cAMP-CRP complex plays a role in the regulation of IS2 transposition. In the gel retardation assay, the cAMP-CRP complex was found to be able to bind the major IS2 promoter. A DNA footprinting assay confirmed that the cAMP-CRP complex binds to the sequences mentioned above. With an IS2 promoter-luciferase gene fusion construct, the cAMP-CRP complex was shown to inhibit transcription from the major IS2 promoter. IS2 was found to transpose at a frequency approximately 200-fold higher in an Escherichia coli host defective for CRP or adenyl cyclase than in a wild-type host. These results suggest that the cAMP-CRP complex is a negative regulator of IS2 transposition.
Hu
S T
ST
Department of Microbiology and Graduate Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, Republic of China. tingnahu@mailsrv.ym.edu.tw
Wang
H C
HC
Lei
G S
GS
Wang
S H
SH
D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism*; D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D016415:Sequence Alignment; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins