Bacterial DNA-dependent RNA polymerase β subunit (RNAP β subunit)

The bacterial DNA-dependent RNA polymerase β subunit is a core component of the multisubunit RNA polymerase (RNAP), which is responsible for the transcription of DNA into RNA in bacteria[3][4][5][6]. The β subunit (encoded by the rpoB gene) is the second-largest component of the enzyme complex and, together with the β′ subunit, forms the catalytic center responsible for RNA synthesis and non-sequence-specific interactions with DNA and nascent RNA[3]. The structure enables the enzyme to recognize, bind, and transcribe DNA templates, a function essential for all gene expression and cell viability in bacteria[5]. Inhibitors of this subunit, such as rifampicin, are clinically important antibiotics, and mutations in the rpoB gene are a chief mechanism behind resistance to these drugs, especially in tuberculosis[6]. The β subunit is highly conserved among bacterial species, but sufficiently distinct from human polymerases to serve as a selective drug target.

Other names

RNA polymerase β subunitRpoBDNA-directed RNA polymerase subunit betaβ subunit of bacterial RNA polymerase

Inhibition of RNA synthesis by binding to the β subunit, blocking the initiation or elongation phase of transcription (e.g., Rifampicin binds near the DNA/RNA channel, preventing RNA chain formation). Stabilization or destabilization of transcription complexes (secondary mechanism for some drugs).