Fis protein forms DNA topological barriers to confine transcription-coupled DNA supercoiling in Escherichiacoli

FEBS Letters

article

Samantha Dages¹  Xiaoduo Zhi¹  Fenfei Leng¹ 

[1] Biomolecular Sciences Institute and Department of Chemistry & Biochemistry, Florida International University

关键词: DNA supercoiling;    DNA topological barriers;    Escherichia coli;    Fis protein;   

DOI  :  10.1002/1873-3468.13643

来源: John Wiley & Sons Ltd.

【 摘 要 】

Previously, we demonstrated that transcription-coupled DNA supercoiling (TCDS) potently activated or inhibited nearby promoters in Escherichia coli even in the presence of all four DNA topoisomerases, suggesting that DNA topoisomerases are not the only factors regulating TCDS. A different mechanism exists to confine this localized DNA supercoiling. Using an in vivo system containing the TCDS-activated leu-500 promoter (Pleu-500), we find that the nucleoid-associated Fis protein potently inhibits the TCDS-mediated activation of Pleu-500. We also find that deletion of the fis gene significantly enhances TCDS-mediated inhibition of transcription of three genes purH, yieP, and yrdA divergently coupled to different rrn operons in the early log phase. These results suggest that Fis protein forms DNA topological barriers upon binding to its recognition sites, blocks TCDS diffusion, and potently inhibits the TCDS-activated Pleu-500.

【 授权许可】

Unknown