DNA-dependent RNA polymerase (RNAP) catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Resistance to the antibiotics salinamide A, salinamide B, rifampicin, streptolydigin, CBR703, myxopyronin, and lipiarmycin can result from mutations in this protein. Part of the processive rRNA transcription and antitermination complex (rrnTAC). The complex forms an RNA-chaperone ring around the RNA exit tunnel of RNAP. It supports rapid transcription and antitermination of rRNA operons, cotranscriptional rRNA folding, and annealing of distal rRNA regions to allow correct ribosome biogenesis. a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) The RNAP catalytic core consists of 2 alpha, 1 beta, 1 beta' and 1 omega subunit. When a sigma factor is associated with the core the holoenzyme is formed, which can initiate transcription. The rRNA transcription and antitermination complex (rrnTAC) consists of RNAP, NusA, NusB, NusE (rpsJ), NusG, SubB, ribosomal protein S4, DNA and precursor rRNA; S4 is more flexible than other subunits (PubMed:32871103). (Microbial infection) Interacts (via flap domain) with Escherichia phage lambda antitermination protein Q; this interaction renders bacterial RNAP resistant to transcription pausing and allows it to read through termination signals. (Microbial infection) Interacts (via flap domain) with the late transcription coactivator of enterobacteria phage T4. Acetylated on several lysine residues in the presence of glucose. Co-administration of salinamide and rifampicin or salinamide and myxopyronin suppresses the emergence of resistance to both antibiotics. Belongs to the RNA polymerase beta chain family.