title: A histone fold TAF octamer within the yeast TFIID transcriptional coactivator.
abstract: Gene activity in a eukaryotic cell is regulated by accessory factors to RNA polymerase II, which include the general transcription factor complex TFIID, composed of TBP and TBP-associated factors (TAFs). Three TAFs that contain histone fold motifs (yTAF17, yTAF60 and yTAF61) are critical for transcriptional regulation in the yeast Saccharomyces cerevisiae and are found in both TFIID and SAGA, a multicomponent histone acetyltransferase transcriptional coactivator. Although these three TAFs were proposed to assemble into a pseudooctamer complex, we find instead that yTAF17, yTAF60 and yTAF61 form a specific TAF octamer complex with a fourth TAF found in TFIID, yTAF48. We have reconstituted this complex in vitro and established that it is an octamer containing two copies each of the four components. Point mutations within the histone folds disrupt the octamer in vitro, and temperature-sensitive mutations in the histone folds can be specifically suppressed by overexpressing the other TAF octamer components in vivo. Our results indicate that the TAF octamer is similar both in stoichiometry and histone fold interactions to the histone octamer component of chromatin.
authors.affiliation: Center for Gene Regulation, Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802-1014, USA.
authors.forename: W
authors.initials: W
authors.lastname: Selleck
authors.forename: R
authors.initials: R
authors.lastname: Howley
authors.forename: Q
authors.initials: Q
authors.lastname: Fang
authors.forename: V
authors.initials: V
authors.lastname: Podolny
authors.forename: M G
authors.initials: MG
authors.lastname: Fried
authors.forename: S
authors.initials: S
authors.lastname: Buratowski
authors.forename: S
authors.initials: S
authors.lastname: Tan
mesh_terms: D000483:Alleles; D002851:Chromatography, High Pressure Liquid; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D006657:Histones / Q000737:chemistry*; D046911:Macromolecular Substances; D008958:Models, Molecular; D008970:Molecular Weight; D035463:Pol1 Transcription Initiation Complex Proteins; D011485:Protein Binding; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity; D013489:Suppression, Genetic / Q000235:genetics; D035381:TATA-Binding Protein Associated Factors; D013696:Temperature; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000737:chemistry* / Q000378:metabolism*; D014461:Ultracentrifugation
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D006657:Histones; D046911:Macromolecular Substances; D035463:Pol1 Transcription Initiation Complex Proteins; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C490039:TAF6 protein, S cerevisiae; C116141:TAF9 protein, S cerevisiae; C491114:TAF12 protein, S cerevisiae