title: Structural basis for dimerization in DNA recognition by Gal4.
abstract: Gal4 is a Zn2Cys6 binuclear cluster containing transcription factor that binds DNA as a homodimer and can activate transcription by interacting with the mutant Gal11P protein. Although structures have been reported of the Gal4 dimerization domain and the binuclear cluster domain bound to DNA as a dimer, the structure of the "complete" Gal4 dimer bound to DNA has not previously been described. Here we report the structure of a complete Gal4 dimer bound to DNA and additional biochemical studies to address the molecular basis for Gal4 dimerization in DNA binding. We find that Gal4 dimerization on DNA is mediated by an intertwined helical bundle that deviates significantly from the solution NMR structure of the free dimerization domain. Associated biochemical studies show that the dimerization domain of Gal4 is important for DNA binding and protein thermostability. We also map the interaction surface of the Gal4 dimerization domain with Gal11P.
authors.affiliation: The Wistar Institute, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Manqing
authors.initials: M
authors.lastname: Hong
authors.forename: Mary X
authors.initials: MX
authors.lastname: Fitzgerald
authors.forename: Sandy
authors.initials: S
authors.lastname: Harper
authors.forename: Cheng
authors.initials: C
authors.lastname: Luo
authors.forename: David W
authors.initials: DW
authors.lastname: Speicher
authors.forename: Ronen
authors.initials: R
authors.lastname: Marmorstein
mesh_terms: D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D008958:Models, Molecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA