Mycobacterial HelD connects RNA polymerase recycling with transcription initiation.

ABSTRACT: Mycobacterial HelD is a transcription factor that recycles stalled RNAP by dissociating it from nucleic acids and, if present, from the antibiotic rifampicin. The rescued RNAP, however, must disengage from HelD to participate in subsequent rounds of transcription. The mechanism of release is unknown. We show that HelD from Mycobacterium smegmatis forms a complex with RNAP associated with the primary sigma factor σ^A and transcription factor RbpA but not CarD. We solve several structures of RNAP-σ^A-RbpA-HelD without and with promoter DNA. These snapshots capture HelD during transcription initiation, describing mechanistic aspects of HelD release from RNAP and its protective effect against rifampicin. Biochemical evidence supports these findings, defines the role of ATP

SUBMITTER: Koval T 

PROVIDER: S-EPMC11464796 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature