Plays an important role in the regulation of rRNA transcription. Binds near or at the enhancer region of rRNA repeating units. May have DNA polymerase activity, but it is not required for in vivo function. a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Stimulated by PCNA and inhibited by aphidicolin. Interacts with FRK1. Present with 4490 molecules/cell in log phase SD medium. Belongs to the MYBBP1A family. Was originally thought to belong to the DNA polymerase type-B family based on conserved motifs (PubMed:12093911). Has later been shown to be unrelated to B class DNA polymerases. The observation of a low level of polymerase activity in vitro, which is not required for its essential cellular function, may require further validation (PubMed:12695662).