DNA-directed RNA polymerase beta subunit, bacterial type (RNAP β subunit)

The DNA-directed RNA polymerase beta subunit is the second-largest subunit of the bacterial multisubunit RNA polymerase core enzyme and is encoded by the rpoB gene. Together with the β′ subunit, it forms the catalytic center essential for RNA synthesis from DNA templates. The β subunit plays a key role in binding nucleotides, catalyzing phosphodiester bond formation, and interacting with DNA and nascent RNA during transcription. This subunit is a well-established antimicrobial target, as several clinically important antibiotics (such as rifampicin) inhibit bacterial RNA polymerase by binding to the β subunit and preventing transcription, particularly in pathogens like Mycobacterium tuberculosis. Mutations in the β subunit can confer drug resistance, making it a molecular biomarker for antibiotic susceptibility testing and treatment monitoring[2][3][4][7].

Other names

Bacterial RNA polymerase β subunitRNA polymerase subunit β (rpoB gene product)RNAP βDNA-dependent RNA polymerase β subunit

Inhibition of RNA synthesis by binding the β subunit and blocking transcription elongation Allosteric inhibition of the RNA polymerase catalytic site