DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Component of RNA polymerase I which synthesizes ribosomal RNA precursors. Through its association with RRN3/TIF-IA may be involved in recruitment of Pol I to rDNA promoters. Component of the RNA polymerase I (Pol I) complex consisting of at least 13 subunits (By similarity). Interacts with RRN3/TIF-IA. Widely expressed. Expressed in all fetal and adult tissues tested, with highest expression in fetal lung, liver, and kidney, and low expression in all adult tissues. Belongs to the eukaryotic RPA43 RNA polymerase subunit family.