InterPro domain: IPR029529

This entry represents transcription factor IIIB subunit Brf1, which is a homologue of the functionally analogous pol II initiation factor, TFIIB [ 1 ]. In budding yeast, Brf1 interacts with several initiation-specific subunits of the pol III machinery, TBP, beta", TFC4p and the pol III subunits C34 and C17 [ 2 ].

Transcription by RNA polymerase III (pol III) is a complex molecular process orchestrated by the two main transcription factors, TFIIIB and TFIIIC. The TFIIIB complex can be recruited by TFIIIC to upstream DNA and form an exceptionally kinetically stable TFIIIB-DNA complex, which then recruits the Pol III enzymatic complex and helps maintain it for multiple transcription cycles in a process called facilitated recycling [ 2 ]. Saccharomyces cerevisiae TFIIIB is a complex of three subunits, the TATA box-binding protein TBP, the TFIIB-related factor BRF, and the beta'' protein.

1. Comparison of the RNA polymerase III transcription machinery in Schizosaccharomyces pombe, Saccharomyces cerevisiae and human. Nucleic Acids Res. 29, 2675-90