RNA polymerase β subunit (β (beta))

The RNA polymerase β subunit is a core catalytic component of the bacterial transcription machinery, encoded by the rpoB gene and characterized by a large structural domain (DPBB) that collaborates with the β′ subunit to form the active center for RNA synthesis. It participates in nucleotide incorporation, transcript elongation, and structural rearrangements during transcription. The β subunit is the direct target of rifampicin-class antibiotics, and mutations in its gene are a key mechanism of antimicrobial resistance. The β-subunit's structural and functional role is highly conserved among bacteria, and although its general function is retained in eukaryotic cells, the homologous subunit in eukaryotes is substantially different, supporting the selectivity of antibiotic targeting.

Other names

Beta subunit of RNA polymeraserpoBRNAP β subunitDNA-directed RNA polymerase subunit β

Drugs such as rifampicin bind to the β-subunit and inhibit its ability to synthesize RNA by stalling the elongation phase of transcription