Component of RNA polymerase I core factor complex (CF) that acts as a sua7/TFIIB-like factor and plays a key role in multiple steps during transcription initiation such as pre-initiation complex (PIC) assembly and postpolymerase recruitment events in polymerase I (Pol I) transcription. Binds HomolD box in rDNA promoters and plays a role in Pol I recruitment. Component of the core factor (CF) complex. Interacts with acr1. Although it shares weak sequence similarity with sua7/TFIIB, displays a similar subdomain organization as sua7/TFIIB, with a N-terminal zinc finger, a connecting region (composed of B-reader and B-linker regions), followed by 2 cyclin folds. Belongs to the RRN7/TAF1B family.