Part of a specialized transcription system that mediates the transcription of most ribosomal proteins through the 5'-TCT-3' motif which is a core promoter element at these genes. Seems to also mediate the transcription of NF1. Does not bind the TATA box (By similarity). Binds TFIIA and TFIIB. Present in the brain, heart, liver and gizzard. Belongs to the TBP family.