title: The glutamine-rich domain of the Drosophila GAGA factor is necessary for amyloid fibre formation in vitro, but not for chromatin remodelling.
abstract: The Drosophila GAGA factor binds specifically to the sequence GAGAG, and synergises with nucleosome remodelling factor to remodel chromatin in vitro. It consists of an N-terminal domain (POZ/BTB) which mediates protein-protein interactions, a central region which contains the DNA-binding domain, and a C-terminal glutamine-rich region. It is shown that the glutamine-rich region is responsible for the formation of fibres in vitro which, on the basis of their tinctorial properties and CD spectra, may be classified as amyloid fibres. A large structural change, probably resulting in beta-sheet structure, is observed upon fibre formation. Mutants containing the central region, either alone or together with the glutamine-rich region, are largely lacking in secondary structure but they bind specifically to the cognate DNA and are able to remodel chromatin in vitro. Consequently, neither the N-terminal domain nor the C-terminal glutamine-rich regions of the GAGA factor are necessary for chromatin remodelling in vitro.
authors.affiliation: Structural Biology Programme, European Molecular Biology Laboratory, Meyerhofstrasse 1 D-69117, Heidelgberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Agianian
authors.forename: K
authors.initials: K
authors.lastname: Leonard
authors.forename: E
authors.initials: E
authors.lastname: Bonte
authors.forename: H
authors.initials: H
authors.lastname: Van der Zandt
authors.forename: P B
authors.initials: PB
authors.lastname: Becker
authors.forename: P A
authors.initials: PA
authors.lastname: Tucker
mesh_terms: D000682:Amyloid / Q000737:chemistry / Q000502:physiology*; D000818:Animals; D052160:Benzothiazoles; D001665:Binding Sites; D001718:Birefringence; D002843:Chromatin / Q000502:physiology*; D003224:Congo Red; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D005456:Fluorescent Dyes; D005973:Glutamine / Q000235:genetics / Q000502:physiology*; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D016296:Mutagenesis; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013329:Structure-Activity Relationship; D013844:Thiazoles; D015534:Trans-Activators / Q000737:chemistry; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D000682:Amyloid; D052160:Benzothiazoles; D002843:Chromatin; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005456:Fluorescent Dyes; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D013844:Thiazoles; D015534:Trans-Activators; D014157:Transcription Factors; C063460:Trl protein, Drosophila; D005973:Glutamine; C009462:thioflavin T; D003224:Congo Red