transcription factor IIIB 50 kD subunit (TFIIIB50, hTFIIIB50, B-related factor 2, BRF-2, hBRFU, BRF2, BRFU, PRO1470)

Function

• general activator of RNA polymerase 3 transcription factor exclusively required for RNA polymerase 3 transcription of genes with promoter elements upstream of initiation sites
• component of TFIIIB complex
• BRF2 recruitment to the TATA box containing small nuclear RNA (snRNA) gene templates is TBP-dependent
• interacts with TBP; this interaction with TBP mediates its TATA-box recruitment of these promoters
• interacts with TBP & the BURE sequence (GC-rich sequence downstream from the TATA box) to form a strong ternary complex which is joined by BDP1; this ternary complex stimulates RNA polymerase 3 transcription
• forms a trimeric complex composed of TBP, BRF2 & mini-SNAPc complex (SNAP43, SNAP50, & the N-terminal 1/3 of SNAP190) on the promoter
• assembly of the TBP-BRF2 complex is stimulated by SNAP190
• interacts with MAF1 & SNAPC4

Cofactor: binds 1 Zn+2 per subunit (putative)

Structure

• belongs to the TFIIB family
• contains 1 TFIIB-type Zn+2 finger

Compartment

nucleus

Expression

• down-regulated by epigallocatechin gallate (EGCG) treatment

More general terms

• nuclear protein
• zinc finger protein
• protein subunit

Component of

• TFIIIB

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5529
• OMIM: https://mirror.omim.org/entry/607013
• UniProt: http://www.uniprot.org/uniprot/Q9HAW0.html