Plasticity of regulation of mannitol phosphotransferase system operon by CRP-cAMP complex in Vibrio cholerae.
OBJECTIVE
The complex of the cyclic AMP receptor protein (CRP) and cAMP is an important transcriptional regulator of numerous genes in prokaryotes. The transport of mannitol through the phosphotransferase systems (PTS) is regulated by the CRP-cAMP complex. The aim of the study is to investigate how the CRP-cAMP complex acting on the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype.


METHODS
The crp mutant strain was generated by homologous recombination to assess the need of CRP to activate the mannitol PTS operon of V. cholerae El Tor. Electrophoretic mobility shift assays (EMSA) and the reporter plasmid pBBRlux were used to confirm the role that the CRP-cAMP complex playing on the mannitol PTS operon mtl.


RESULTS
In this study, we confirmed that CRP is strictly needed for the activation of the mtl operon. We further experimentally identified five CRP binding sites within the promoter region upstream of the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype and found that these sites display different affinities for CRP and provide different contributions to the activation of the operon.


CONCLUSIONS
The five binding sites collectively confer the strong activation of mannitol transfer by CRP in V. cholerae, indicating an elaborate and subtle CRP activation mechanism.
State Key Laboratory for Communicable Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Yan Yan
YY
Zhou
Hong Zhi
HZ
Zhang
Wei Li
WL
Liang
Li Juan
LJ
Zhang
Jun
J
Zhu
Biao
B
Kan
D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D000242:Cyclic AMP / Q000378:metabolism; D002373:Cyclic AMP Receptor Protein; D015964:Gene Expression Regulation, Bacterial; D008353:Mannitol; D008969:Molecular Sequence Data; D009876:Operon; D010770:Phosphotransferases; D014734:Vibrio cholerae
D001426:Bacterial Proteins; D002373:Cyclic AMP Receptor Protein; D008353:Mannitol; D000242:Cyclic AMP; D010770:Phosphotransferases
CRP-binding sites; CRP-cAMP complex; Cyclic AMP receptor protein; Vibrio cholerae