H-NS binding on dicA promoter DNA inhibits dicA gene expression

dicA promoter DNA에 붙는 H-NS 단백질에 의한 dicA 유전자의 발현 조절

  • Yun, Sang Hoon (Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University) ;
  • Lee, Yonho (Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University) ;
  • Lim, Heon M. (Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University)
  • 윤상훈 (충남대학교 생명시스템과학대학 생물과학과) ;
  • 이연호 (충남대학교 생명시스템과학대학 생물과학과) ;
  • 임헌만 (충남대학교 생명시스템과학대학 생물과학과)
  • Received : 2019.07.05
  • Accepted : 2019.08.26
  • Published : 2019.09.30


H-NS binds to promoter DNA and works as a general transcription silencer. DicA protein, by binding to the promoter DNA of dicA, activates dicA expression and at the same time inhibits expression of dicF and dicB, thus, exerting cell division control in Escherichia coli. H-NS complexed with a nucleoid protein Cnu was known to be involved in dicA expression. However, the exact nature of H-NS binding to dicA promoter DNA and the consequences of H-NS binding in expression of dicA is not clear. In this study, we explored the DNA binding activity of H-NS on the promoter DNA of dicA and found that H-NS binding occurs exclusively to the dicA promoter DNA. We never observed, however, H-NS binding at the vicinity of the dicA promoter. Temperature dependent oligomerization of H-NS was observed during DNA binding and the Cnu protein enhances the oligomerization process of H-NS binding. In vivo measurement of dicA expression in an hns deleted strain showed that dicA expression increased. These results demonstrated that H-NS binds specifically to dicA promoter DNA and functions as a transcription silencer.


Escherichia coli;Cnu;dicA;filamentous growth;H-NS;temperature-dependent DNA binding


Supported by : 충남대학교


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