Histone-like nucleoid structuring (H-NS) protein silences the beta-glucoside (bgl) utilization operon in Escherichia coli by forming a DNA loop.

ABSTRACT: The bgl operon of Escherichia coli encodes proteins mediating the metabolism of aromatic beta-glucosides, but the operon is silent in wild type cells. Insertion of an insertion sequence (IS) element in the regulatory region upstream of the bgl promoter activates expression of the operon. The repression mechanism involves the histone-like nucleoid structuring (H-NS) protein with two DNA binding sites, one in the region upstream of the promoter, and the other within the first structural gene of the operon, bglG. The detailed mechanism of repression is not well understood. Here, we first show two terminators flanking bglG are not required for bgl operon silencing. Instead, several lines of experimental evidence clearly suggest that the silencing mecha

SUBMITTER: Lam KJK 

PROVIDER: S-EPMC9678765 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature