DNA-directed RNA polymerase, bacterial (RNAP (often also abbreviated as DdRP for DNA-dependent RNA polymerase in some literature))

DNA-directed RNA polymerase, bacterial is a crucial, multisubunit enzyme complex responsible for transcription—the process of synthesizing RNA from a DNA template in bacteria[1][2][3][4][5]. The core enzyme consists of five conserved subunits (β, β′, two α, and ω), with a total molecular mass of around 380–400 kDa. Transcription initiation requires association with a σ (sigma) factor, which allows promoter-specific binding; together, these form the RNAP holoenzyme[1][3][4][5]. RNAP binds to double-stranded DNA, unwinds it, and catalyzes the polymerization of ribonucleotides into messenger RNA and other RNA species in the 5′–3′ direction[2][3][4]. This target is exploited in bacterial infection treatments by antibiotics like rifampicin, which specifically inhibit its function[2][3]. Resistance to these drugs can occur via mutations in target subunits (notably rpoB)[3]. RNAP's central role in gene expression makes it essential for bacterial survival and a key molecule for both research and therapy[1][2][3][5].

Other names

Bacterial RNA polymeraseDNA-dependent RNA polymeraseRNAPDdRP

Inhibition of initiation of transcription (e.g., rifampicin binds to the β subunit, blocking RNA synthesis at early stages); Interference with RNA chain elongation (other antibiotics can obstruct the nucleotide addition process); Disruption of proper holoenzyme formation (some drugs target interaction with sigma factors and holoenzyme assembly)