What type of RNAP does Rifampicin inhibit?

Rifampicin specifically inhibits bacterial RNA polymerase, thereby effectively targeting prokaryotic RNAP. This antibiotic works by binding to the beta-subunit of the prokaryotic RNA polymerase enzyme, preventing the initiation of RNA synthesis. As a result, it has a profound impact on the ability of bacteria to produce RNA, thereby stunting their growth and proliferation.

In contrast, eukaryotic RNA polymerases have different structural and functional characteristics; they possess additional subunits and employ different mechanisms for transcription initiation. Rifampicin does not bind to eukaryotic RNA polymerases, which illustrates its specificity for prokaryotic organisms. Thus, the correct answer accurately reflects the selective action of Rifampicin on prokaryotic RNA polymerase.