title: Structure of the sporulation-specific transcription factor Ndt80 bound to DNA.
abstract: Progression through the middle phase of sporulation in Saccharomyces cerevisiae is promoted by the successful completion of recombination at the end of prophase I. Completion of meiotic recombination allows the activation of the sporulation-specific transcription factor Ndt80, which binds to a specific DNA sequence, the middle sporulation element (MSE), and activates approximately 150 genes to enable progression through meiosis. Here, we isolate the DNA-binding domain of Ndt80 and determine its crystal structure both free and in complex with an MSE-containing DNA. The structure reveals that Ndt80 is a member of the Ig-fold family of transcription factors. The structure of the DNA-bound form, refined at 1.4 A, reveals an unexpected mode of recognition of 5'-pyrimidine- guanine-3' dinucleotide steps by arginine residues that simultaneously recognize the 3'-guanine base through hydrogen bond interactions and the 5'-pyrimidine through stacking/van der Waals interactions. Analysis of the DNA-binding affinities of MSE mutants demonstrates the central importance of these interactions, and of the AT-rich portion of the MSE. Functional similarities between Ndt80 and the Caenorhabditis elegans p53 homolog suggest an evolutionary link between Ndt80 and the p53 family.
authors.affiliation: Department of Biochemistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
authors.forename: Jason S
authors.initials: JS
authors.lastname: Lamoureux
authors.forename: David
authors.initials: D
authors.lastname: Stuart
authors.forename: Roger
authors.initials: R
authors.lastname: Tsang
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wu
authors.forename: J N Mark
authors.initials: JN
authors.lastname: Glover
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004271:DNA, Fungal / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D008540:Meiosis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013172:Spores, Fungal; D014157:Transcription Factors
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C097071:NDT80 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors