journals.asm.org
TrbA binds and locks a sliding clamp KorB to repress transcription on multi-drug resistance plasmids | Journal of Bacteriology
Precise regulation of gene expression ensures gene products are produced at the right time and in the right amounts. Recent works uncovered a new mechanism of bacterial gene regulation based on a clamp sliding and locking in a multi-drug resistance plasmid, RK2. KorB functions as a CTP-dependent DNA-sliding clamp capable of traveling over a long genomic distance. Sliding KorB is captured and locked in place by a partner protein, KorA, forming a stable complex at target promoters to repress transcription. Here, we show that another RK2 regulator, TrbA, also uses this clamp sliding-locking mechanism, and identify an aromatic interface enabling TrbA-KorB-mediated transcriptional repression. Our findings show how a single sliding clamp integrates multiple partners to build a complex transcriptional regulatory network.
