Structural basis of transcriptional activation by the Mycobacterium tuberculosis intrinsic antibiotic-resistance transcription factor WhiB7.

ABSTRACT: In pathogenic mycobacteria, transcriptional responses to antibiotics result in induced antibiotic resistance. WhiB7 belongs to the Actinobacteria-specific family of Fe-S-containing transcription factors and plays a crucial role in inducible antibiotic resistance in mycobacteria. Here, we present cryoelectron microscopy structures of Mycobacterium tuberculosis transcriptional regulatory complexes comprising RNA polymerase σ^A-holoenzyme, global regulators CarD and RbpA, and WhiB7, bound to a WhiB7-regulated promoter. The structures reveal how WhiB7 interacts with σ^A-holoenzyme while simultaneously interacting with an AT-rich sequence element via its AT-hook. Evidently, AT-hooks, rare elements in bacteria yet prevalent in eukaryotes, bind to target AT-rich DNA sequences

SUBMITTER: Lilic M 

PROVIDER: S-EPMC8311663 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature