The ω subunit stabilizes transcribing RNA polymerase to balance processivity and collision resolution

Le résumé fourni par la source

Abstract The ubiquitous subunit of RNA polymerase (RNAP), ω/RPB6, is traditionally viewed as an assembly chaperone or bacterial σ-factor competition modulator. This study redefines the role of Escherichia coli ω, encoded by the rpoZ gene. Unexpectedly, ΔrpoZ strain does not exhibit major defects in σ S -dependent stress responses, indicating its primary function lies elsewhere. Our CRISPRi screen suggested that losing ω may promote survival during transcription-replication conflicts. Consistently, we show that loss of ω sensitizes RNAP to termination, reduces RNAP processivity, and suppresses toxic effects of DNA-damaging agents in strains lacking functional DksA, Rho, or SeqA; DksA and Rho promote the release of stalled RNAP from nucleic acids, while SeqA prevents aberrant replication initiation. These findings suggest that loss of ω facilitates the removal of stalled RNAP, preventing catastrophic replisome collisions. We propose that ω/RPB6 homologs may balance RNAP processivity with controlled release to preserve genome integrity across all domains of life.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.