DNA-dependent RNA polymerase from Mycobacterium tuberculosis (RNAP (sometimes abbreviated Rpo))

Mycobacterial DNA-dependent RNA polymerase is a multi-subunit enzyme essential for bacterial viability. It catalyzes the transcription of DNA into RNA, a process crucial for gene expression and survival of *Mycobacterium tuberculosis*. The enzyme consists of a core complex (subunits α, β, β') often combined with sigma factors for promoter recognition and transcription initiation. Rifampin and related drugs target this enzyme, binding the β subunit (encoded by rpoB), and directly inhibit RNA synthesis, making it a proven and critical therapeutic target for tuberculosis therapy. Mutations in the rpoB subunit are the primary mechanism for the development of resistance to rifampin, contributing to the global challenge of multi-drug-resistant tuberculosis. The enzyme is structurally and functionally distinct from human RNA polymerases, supporting its selective targeting in antimicrobial drug development.

Other names

Mycobacterial RNA polymeraseMtb RNA polymeraseRNAPRpoB (core β subunit)RpoA (core α subunit)RpoC (core β' subunit)

Drugs inhibit RNA synthesis by binding the core enzyme, halting transcription. Prevents elongation or initiation of nascent RNA strand