NMR evidence for similarities between the DNA-binding regions of Drosophila melanogaster heat shock factor and the helix-turn-helix and HNF-3/forkhead families of transcription factors

• Published in: Biochemistry (Easton) Vol. 33; no. 1; pp. 10 - 16
• Main Authors: Vuister, Geerten W, Kim, Soon Jong, Wu, Carl, Bax, Ad
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.01.1994
• Subjects: ADN; Amino Acid Sequence; Animals; Binding Sites; Biological and medical sciences; DNA - chemistry; DNA - metabolism; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - metabolism; DROSOPHILA MELANOGASTER; Drosophila melanogaster - metabolism; ESPECTROSCOPIA RMN; Fundamental and applied biological sciences. Psychology; Heat-Shock Proteins - chemistry; Heat-Shock Proteins - metabolism; Helix-Loop-Helix Motifs; Hepatocyte Nuclear Factor 3-gamma; Hydrogen Bonding; Magnetic Resonance Spectroscopy - methods; Models, Structural; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Protein Structure, Secondary; PROTEINAS; PROTEINE; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; SPECTROSCOPIE RMN; Transcription Factors; Transcription. Transcription factor. Splicing. Rna processing; Insecta; Drosophila; Homology; Binding site; NMR spectrometry; N dimensional spectrometry; Secondary structure; Drosophilidae; Arthropoda; DNA; Transcription factor HSF; Invertebrata; Molecular domain; Diptera; Structural analysis
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi00167a002

Heteronuclear multidimensional NMR experiments of residues 33-163 of the DNA-binding domain of Drosophila heat shock factor, dHSF(33-163), were recorded, using only 3 mg of uniformly 15N-labeled or 2 mg of uniformly 15N/13C-labeled protein. The polypeptide consists of a structured part comprising three helices, a three-stranded antiparallel beta-sheet, with the first two strands connected by a four-residue type I tight turn. The second helix is disrupted at its C-terminal end by a proline residue and is followed by an extended turn, leading to the third helix. The dHSF(33-163) protein is unstructured at its N- and C-termini, and a third unstructured region is found from Thr113 to Arg124. Exchange broadening of the 15N-1H correlations upon titration of 15N labeled HSF with a 13-base-pair DNA duplex suggests a DNA-binding motif in which the third helix acts as the recognition helix. Both the secondary structure and DNA-binding pattern of dHSF(33-163) suggest that the overall topology resembles that the helix-turn-helix bacterial activator CAP [Weber, I.T., and Steitz, T.A. (1987) J. Mol. Biol. 198, 311-326] and the liver-specific transcription factor HNF-3 gamma, the prototype of the HNF-3/forkhead protein family