BRF1/YGR246C Summary Help

Standard Name BRF1 1
Systematic Name YGR246C
Alias PCF4 , TDS4
Feature Type ORF, Verified
Description TFIIIB B-related factor; one of three subunits of RNA polymerase III transcription initiation factor TFIIIB, binds TFIIIC and TBP and recruits RNA pol III to promoters, amino-terminal half is homologous to TFIIB (2, 3, 4 and see Summary Paragraph)
Name Description B-Related Factor 3
Gene Product Alias TFIIIB70 5
Chromosomal Location
ChrVII:984272 to 982482 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All BRF1 GO evidence and references
  View Computational GO annotations for BRF1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Targets 18 genes
Regulators 1 genes
Classical genetics
Large-scale survey
reduction of function
70 total interaction(s) for 34 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 9
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 5
  • Co-crystal Structure: 1
  • Reconstituted Complex: 12
  • Two-hybrid: 12

Genetic Interactions
  • Dosage Rescue: 13
  • Negative Genetic: 15
  • Synthetic Lethality: 1
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 596
Molecular Weight (Da) 66,906
Isoelectric Point (pI) 6.91
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrVII:984272 to 982482 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1791 984272..982482 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000003478

The TFIIIB complex is a initiation factor for RNA polymerase III, which transcribes tRNAs, most small nuclear RNAs, and 5S rRNA (reviewed in 6). TFIIIB, comprised of TBP (Spt15p), Brf1p, and Bdp1p, directs pol III to the transcriptional start site of these genes and is itself recruited to a location immediately upstream of the transcriptional start site by the TFIIIC complex (2). TFIIIB binds to TFIIIC mainly through contact between TFIIIB subunits Brf1p and Bdp1p and the TFIIIC subunit Tfc4p, and between TBP and the TFIIIC subunit Tfc8p (7, 8). The TFIIIB footprint on promoter DNA is influenced by the DNA-binding site preferences of the TBP subunit and by the non-histone chromatin proteins Nhp6Ap and Nhp6bp (9 and reviewed in 10). TFIIIB function is also important for promoter opening (via the Brf1p and Bdp1p subunits), reinitiation of pol III transcription, and targeting and efficiency of Ty3 retrotransposition (11, 12, and 13). TFIIIB is also the target of Maf1-mediated repression of pol III transcription (reviewed in 14).

BRF1 is an essential gene and encodes a structurally bipartite protein. The N-terminal half is similar to the transcription factor TFIIB (Sua7p) and the C-terminal half is specific for pol III function and contains the primary interaction sites for the other TFIIIB subunits (15 and reviewed in 14). Brf1p also functions to dissociate inactive TBP homodimers into active monomers (16).

Humans have two Brf1p paralogs, BRF1 and BRF2, which are found in distinct TFIIIB complexes that are involved in transcriptional activation at different sets of promoters (reviewed in 17 and 6). Tumor suppressor gene products such as BRCA1 repress pol III transcription by targeting the TFIIIB complex (18 and references therein).

Last updated: 2010-02-26 Contact SGD

References cited on this page View Complete Literature Guide for BRF1
1) Colbert T and Hahn S  (1992) A yeast TFIIB-related factor involved in RNA polymerase III transcription. Genes Dev 6(10):1940-9
2) Kassavetis GA, et al.  (1997) Domains of the Brf component of RNA polymerase III transcription factor IIIB (TFIIIB): functions in assembly of TFIIIB-DNA complexes and recruitment of RNA polymerase to the promoter. Mol Cell Biol 17(9):5299-306
3) Khoo B, et al.  (1994) Conserved functional domains of the RNA polymerase III general transcription factor BRF. Genes Dev 8(23):2879-90
4) Kassavetis GA, et al.  (1998) Functional and structural organization of Brf, the TFIIB-related component of the RNA polymerase III transcription initiation complex. Mol Cell Biol 18(9):5587-99
5) Andrau JC, et al.  (1999) Mutagenesis of yeast TFIIIB70 reveals C-terminal residues critical for interaction with TBP and C34. J Mol Biol 288(4):511-20
6) Geiduschek EP and Kassavetis GA  (2001) The RNA polymerase III transcription apparatus. J Mol Biol 310(1):1-26
7) Chaussivert N, et al.  (1995) Complex interactions between yeast TFIIIB and TFIIIC. J Biol Chem 270(25):15353-8
8) Deprez E, et al.  (1999) A subunit of yeast TFIIIC participates in the recruitment of TATA-binding protein. Mol Cell Biol 19(12):8042-51
9) Kassavetis GA and Steiner DF  (2006) Nhp6 is a transcriptional initiation fidelity factor for RNA polymerase III transcription in vitro and in vivo. J Biol Chem 281(11):7445-51
10) Geiduschek EP  (2009) Without a license, or accidents waiting to happen. Annu Rev Biochem 78:1-28
11) Kassavetis GA, et al.  (2001) The RNA polymerase III transcription initiation factor TFIIIB participates in two steps of promoter opening. EMBO J 20(11):2823-34
12) Ferrari R, et al.  (2004) Distinct roles of transcription factors TFIIIB and TFIIIC in RNA polymerase III transcription reinitiation. Proc Natl Acad Sci U S A 101(37):13442-7
13) Yieh L, et al.  (2002) Mutational analysis of the transcription factor IIIB-DNA target of Ty3 retroelement integration. J Biol Chem 277(29):25920-8
14) Ciesla M and Boguta M  (2008) Regulation of RNA polymerase III transcription by Maf1 protein. Acta Biochim Pol 55(2):215-25
15) Kassavetis GA, et al.  (2006) Mapping the principal interaction site of the Brf1 and Bdp1 subunits of Saccharomyces cerevisiae TFIIIB. J Biol Chem 281(20):14321-9
16) Alexander DE, et al.  (2004) Inhibition of TATA binding protein dimerization by RNA polymerase III transcription initiation factor Brf1. J Biol Chem 279(31):32401-6
17) Kassavetis GA and Geiduschek EP  (2006) Transcription factor TFIIIB and transcription by RNA polymerase III. Biochem Soc Trans 34(Pt 6):1082-7
18) Veras I, et al.  (2009) Inhibition of RNA Polymerase III Transcription by BRCA1. J Mol Biol 387(3):523-31