| 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 | |
|---|---|
| Note: this feature is encoded on the Crick strand. | |
| View Computational GO annotations for BRF1 | |
| Molecular Function | |
| Manually curated | |
| Biological Process | |
| Manually curated | |
| Cellular Component | |
| Manually curated |
| Classical genetics | |
|---|---|
| conditional | |
| null | |
| repressible | |
| Large-scale survey | |
| null | |
| overexpression | |
| reduction of function | |
| Resources |
| 69 total interaction(s) for 34 unique genes/features. | |
| Physical Interactions |
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| Genetic Interactions |
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| Resources |
| Localization | |
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| Phosphorylation | PhosphoGRID | PhosphoPep Database |
| Structure | |
| Homologs |
| Note: this feature is encoded on the Crick strand. | |||||||||||||
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| Last Update | Coordinates: 2011-02-03 | Sequence: 1996-07-31 | ||||||||||||
| Subfeature details |
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| Retrieve sequences | |||||||||||||
| 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 |
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| Primary SGDID | S000003478 |
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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).
| 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 |





