title: Solution structure of the DNA-binding domain of the tomato heat-stress transcription factor HSF24.
abstract: Two-dimensional-NMR and three-dimensional-NMR experiments were performed to determine the solution structure of the DNA-binding domain of the tomato heat-stress transcription factor HSF24. Samples of uniformly 15N-labeled and 15N, 13C-labeled recombinant proteins were used in the investigation. A near-complete assignment of the backbone 1H, 15N, and 13C resonances was obtained by three-dimensional triple-resonance experiments, whereas three-dimensional 15N-TOCSY-heteronuclear-single-quantum-correlation-spectroscopy, HCCH-COSY and HCCH-TOCSY spectra were recorded for side-chain assignments, 885 non-redundant distance constraints from two-dimensional-homonuclear and three-dimensional-15N-edited and 13C-edited NOESY spectra and 40 hydrogen-bond constraints from exchange experiments were used for structure calculations. The resulting three-dimensional structure contains a three-helix bundle and a small four-stranded antiparallel beta-sheet that forms a hydrophobic core. The two C-terminal helices are parts of a highly conserved helix-turn-helix motif that is probably involved in DNA recognition and binding. In contrast to heat-stress factors from yeast and animals, the plant heat-stress factors lack a loop of 11 amino acid residues inserted between beta3 and beta4. This leads to a tight turn between these beta-strands.
authors.affiliation: Department of Biophysical Chemistry, Biocenter of the Goethe-Universität, Frankfurt, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schultheiss
authors.forename: O
authors.initials: O
authors.lastname: Kunert
authors.forename: U
authors.initials: U
authors.lastname: Gase
authors.forename: K D
authors.initials: KD
authors.lastname: Scharf
authors.forename: L
authors.initials: L
authors.lastname: Nover
authors.forename: H
authors.initials: H
authors.lastname: Rüterjans
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003198:Computer Simulation; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006860:Hydrogen Bonding; D018551:Solanum lycopersicum / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012996:Solutions; D013379:Substrate Specificity; D015534:Trans-Activators / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C098034:HSF24 protein, Lycopersicon peruvianum; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D012996:Solutions; D015534:Trans-Activators