RNA polymerase beta subunit (bacterial) (β subunit (bacterial RNAP) or RpoB)

The **bacterial RNA polymerase beta subunit** (commonly referred to as the **β subunit** or **RpoB**) is one of the core subunits of the bacterial DNA-dependent RNA polymerase enzyme complex, which catalyzes the synthesis of RNA from a DNA template during transcription[3][7][8]. The β subunit, encoded by the rpoB gene, forms part of the catalytic center with the β′ subunit and provides key sites for the binding of DNA, nascent RNA, and for the action of crucial antibiotics[3][8]. It is a major target of rifampicin and related drugs, and specific mutations in rpoB lead to drug resistance, making it clinically significant for the treatment and monitoring of bacterial infections, especially tuberculosis[3]. The β subunit’s structure plays a central role in coordinating catalytic activity, facilitating nucleic acid interactions, and interacting with transcriptional regulators and inhibitors[5][7][8].

Other names

RNA polymerase β subunitRpoBDNA-directed RNA polymerase subunit beta (bacterial)RNAP betaRNAP β

Inhibition of RNA synthesis by binding to the beta subunit and blocking the formation of the RNA chain (e.g., rifampicin binds to β subunit, preventing elongation of RNA transcript)