A new use for the 'wing' of the 'winged' helix-turn-helix motif in the HSF-DNA cocrystal

Nat Struct Biol. 1999 May;6(5):464-70. doi: 10.1038/8269.

Abstract

The 1.75 A crystal structure of the Kluyveromyces lactis heat shock transcription factor (HSF) DNA-binding domain (DBD) complexed with DNA reveals a protein-DNA interface with few direct major groove contacts and a number of phosphate backbone contacts that are primarily water-mediated interactions. The DBD, a 'winged' helix-turn-helix protein, displays a novel mode of binding in that the 'wing' does not contact DNA like all others of that class. Instead, the monomeric DBD, which crystallized as a symmetric dimer to a pair of nGAAn inverted repeats, uses the 'wing' to form part of the protein-protein contacts. This dimer interface is likely important for increasing the DNA-binding specificity and affinity of the trimeric form of HSF, as well as for increasing cooperativity between adjacent trimers.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Crystallization
  • Crystallography, X-Ray
  • DNA / chemistry
  • DNA / metabolism*
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / metabolism
  • Dimerization
  • Fungal Proteins / chemistry*
  • Fungal Proteins / metabolism
  • Heat-Shock Proteins / chemistry*
  • Heat-Shock Proteins / metabolism
  • Helix-Turn-Helix Motifs / physiology*
  • Hydrogen Bonding
  • Kluyveromyces / chemistry*
  • Models, Molecular
  • Molecular Sequence Data
  • Peptide Fragments / chemistry*
  • Peptide Fragments / metabolism
  • Phosphates / metabolism
  • Protein Binding
  • Protein Conformation
  • Response Elements / genetics
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Transcription Factors / chemistry*
  • Transcription Factors / metabolism
  • Water / metabolism

Substances

  • DNA-Binding Proteins
  • Fungal Proteins
  • HSF1 protein, S cerevisiae
  • Heat-Shock Proteins
  • Peptide Fragments
  • Phosphates
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Water
  • DNA

Associated data

  • PDB/3HTS