Fis protein forms DNA topological barriers to confine transcription-coupled DNA supercoiling in Escherichia coli.

ABSTRACT: 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 (P_leu-500 ), we find that the nucleoid-associated Fis protein potently inhibits the TCDS-mediated activation of P_leu-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 sugges

SUBMITTER: Dages S 

PROVIDER: S-EPMC10857741 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature