title: Regulatory effects of cAMP receptor protein (CRP) on porin genes and its own gene in Yersinia pestis.
abstract: BACKGROUND
  The cAMP receptor protein (CRP) is a global bacterial regulator that controls many target genes. The CRP-cAMP complex regulates the ompR-envZ operon in E. coli directly, involving both positive and negative regulations of multiple target promoters; further, it controls the production of porins indirectly through its direct action on ompR-envZ. Auto-regulation of CRP has also been established in E. coli. However, the regulation of porin genes and its own gene by CRP remains unclear in Y. pestis.
  
  
  RESULTS
  Y. pestis employs a distinct mechanism indicating that CRP has no regulatory effect on the ompR-envZ operon; however, it stimulates ompC and ompF directly, while repressing ompX. No transcriptional regulatory association between CRP and its own gene can be detected in Y. pestis, which is also in contrast to the fact that CRP acts as both repressor and activator for its own gene in E. coli. It is likely that Y. pestis OmpR and CRP respectively sense different signals (medium osmolarity, and cellular cAMP levels) to regulate porin genes independently.
  
  
  CONCLUSIONS
  Although the CRP of Y. pestis shows a very high homology to that of E. coli, and the consensus DNA sequence recognized by CRP is shared by the two bacteria, the Y. pestis CRP can recognize the promoters of ompC, F, and X directly rather than that of its own gene, which is different from the relevant regulatory circuit of E. coli. Data presented here indicate a remarkable remodeling of the CRP-mediated regulation of porin genes and of its own one between these two bacteria.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
authors.forename: He
authors.initials: H
authors.lastname: Gao
authors.forename: Yiquan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.forename: Zhaobiao
authors.initials: Z
authors.lastname: Guo
authors.forename: Yafang
authors.initials: Y
authors.lastname: Tan
authors.forename: Yanping
authors.initials: Y
authors.lastname: Han
authors.forename: Xinxiang
authors.initials: X
authors.lastname: Huang
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Zhou
authors.forename: Ruifu
authors.initials: R
authors.lastname: Yang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002373:Cyclic AMP Receptor Protein / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D009876:Operon; D018272:Porins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D015010:Yersinia pestis / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002373:Cyclic AMP Receptor Protein; D018272:Porins; D012329:RNA, Bacterial; D015534:Trans-Activators; C112177:osmolarity response regulator proteins