The ω subunit stabilizes transcribing RNA polymerase to balance processivity and DNA repair

Our biochemical data showed no differences in initiation, elongation, pausing, or two model phage terminators (T7 and P14), in the presence or absence of ω. But ω deletion increased termination at NusA-dependent (rscX), or ribosomal (rrnB T1) terminators. RNA-seq profiling of the E. coli ΔrpoZ clean deletion strain did not show significant changes in gene expression for genes showing altered Δω RNAP-distribution, or genes controlled by σS. Finally, CRISPRi screening for WT and ΔrpoZ strains suggested that Rho and DksA could potentially influence ω function.

Subsequent analysis of strains lacking DksA and having reduced expression of Rho showed that the rpoZ deletion increases survival in the presence of genotoxic agents and suggested that ω may stabilize the EC in vivo to modulate the resolution of collisions between RNA polymerase and replisome.