title: A stable complex of a novel transcription factor IIB- related factor, human TFIIIB50, and associated proteins mediate selective transcription by RNA polymerase III of genes with upstream promoter elements.
abstract: Transcription factor IIIB (TFIIIB) is directly involved in transcription initiation by RNA polymerase III in eukaryotes. Yeast contain a single TFIIIB activity that is comprised of the TATA-binding protein (TBP), TFIIB-related factor 1 (BRF1), and TFIIIB", whereas two distinct TFIIIB activities, TFIIIB-alpha and TFIIIB-beta, have been described in human cells. Human TFIIIB-beta is required for transcription of genes with internal promoter elements, and contains TBP, a TFIIIB" homologue (TFIIIB150), and a BRF1 homologue (TFIIIB90), whereas TFIIIB-alpha is required for transcription of genes with promoter elements upstream of the initiation site. Here we describe the identification, cloning, and characterization of TFIIIB50, a novel homologue of TFIIB and TFIIIB90. TFIIIB50 and tightly associated factors, along with TBP and TFIIIB150, reconstitute human TFIIIB-alpha activity. Thus, higher eukaryotes, in contrast to the yeast Saccharomyces cerevisiae, have evolved two distinct TFIIB-related factors that mediate promoter selectivity by RNA polymerase III.
authors: Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
authors: M
authors: M
authors: Teichmann
authors: Z
authors: Z
authors: Wang
authors: R G
authors: RG
authors: Roeder
mesh_terms: D001483:Base Sequence; D002458:Cell Fractionation; D018076:DNA, Complementary; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035581:Transcription Factor TFIIB; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C090956:BRF1 protein, S cerevisiae; C441028:BRF1 protein, human; D018076:DNA, Complementary; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035581:Transcription Factor TFIIB; D035361:Transcription Factor TFIIIB; D014157:Transcription Factors; D012320:RNA Polymerase III