title: Molecular architecture of the S. cerevisiae SAGA complex.
abstract: The Saccharomyces cerevisiae SAGA complex is a multifunctional coactivator that regulates transcription by RNA polymerase II. The 3D structure of SAGA, revealed by electron microscopy, is formed by five modular domains and shows a high degree of structural conservation to human TFTC, reflecting their related subunit composition. The positions of several SAGA subunits were mapped by immunolabeling and by analysis of mutant complexes. The Taf (TBP-associated factor) subunits, shared with TFIID, occupy a central region in SAGA and form a similar structure in both complexes. The locations of two histone fold-containing core subunits, Spt7 and Ada1, are consistent with their role in providing a SAGA-specific interface with the Tafs. Three components that perform distinct regulatory functions, Spt3, Gcn5, and Tra1, are spatially separated, underscoring the modular nature of the complex. Our data provide insights into the molecular architecture of SAGA and imply a functional organization to the complex.
authors.affiliation: Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Pei-Yun Jenny
authors.initials: PY
authors.lastname: Wu
authors.forename: Christine
authors.initials: C
authors.lastname: Ruhlmann
authors.forename: Fred
authors.initials: F
authors.lastname: Winston
authors.forename: Patrick
authors.initials: P
authors.lastname: Schultz
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins / Q000502:physiology; D051548:Histone Acetyltransferases; D015394:Molecular Structure; D011494:Protein Kinases / Q000502:physiology; D011506:Proteins / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry* / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology; D035362:Transcription Factor TFIID / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology; D014158:Transcription, Genetic / Q000502:physiology*; D000099224:p300-CBP-Associated Factor
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; D051548:Histone Acetyltransferases; D011494:Protein Kinases; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D014157:Transcription Factors; C106162:HFI1 protein, S cerevisiae; C099690:SPT20 protein, S cerevisiae; C075582:SPT3 protein, S cerevisiae; C093107:SPT7 protein, S cerevisiae; C491364:TRA1 protein, S cerevisiae; C501392:GCN5 protein, S cerevisiae; D000099224:p300-CBP-Associated Factor