title: Secondary structure of the lac repressor DNA-binding domain by two-dimensional 1H nuclear magnetic resonance in solution.
abstract: A recently proposed approach for spatial structure determination in noncrystalline proteins by nuclear magnetic resonance was applied to the lac repressor DNA-binding domain. On the basis of sequence-specific 1H NMR assignments, the location of alpha-helices in the amino acid sequence was determined from nuclear Overhauser enhancement data and from amide proton exchange studies. These investigations provide detailed experimental data on the structure of a noncrystalline DNA-binding protein. The results support the hypothesis advanced by others that sequence-specific interactions between lac repressor and DNA are mediated by a particular spatial arrangement of two alpha-helices common to various different DNA-binding proteins.
mesh_terms: D000595:Amino Acid Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D007763:Lac Operon; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D012097:Repressor Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors