Structural basis of direct and inverted DNA sequence repeat recognition by helix-turn-helix transcription factors.

ABSTRACT: Some transcription factors bind DNA motifs containing direct or inverted sequence repeats. Preference for each of these DNA topologies is dictated by structural constraints. Most prokaryotic regulators form symmetric oligomers, which require operators with a dyad structure. Binding to direct repeats requires breaking the internal symmetry, a property restricted to a few regulators, most of them from the AraC family. The KorA family of transcriptional repressors, involved in plasmid propagation and stability, includes members that form symmetric dimers and recognize inverted repeats. Our structural analyses show that ArdK, a member of this family, can form a symmetric dimer similar to that observed for KorA, yet it binds direct sequence repeats as a non-symmetric dimer. This is possible by

SUBMITTER: Fernandez-Lopez R 

PROVIDER: S-EPMC9723621 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature