title: Two-dimensional NMR study of a protein-DNA complex. lac repressor headpiece-operator interaction.
abstract: The interaction of the N-terminal DNA-binding domain (56 amino acid residues) of the lac repressor with lac operator DNA was analyzed using two-dimensional NMR spectroscopy. Both half-operators (11 and 14 bp) and a complete fully symmetric 22 bp operator were studied. Two-dimensional nuclear Overhauser effect (2D NOE) spectra of headpiece-operator complexes were taken in both D2O and H2O solutions. Special attention was given to the problem of 1H resonance assignments. Based on an analysis of the proton-proton NOEs, a model for the headpiece-operator complex could be derived. In this model, most of the protein-DNA contracts occur between amino acid residues in the second helix (recognition helix) of the lac headpiece and DNA bases in the major groove. The orientation of this helix with respect to the dyad axis of the operator is opposite to that found in the X-ray structures of several other repressor-operator complexes.
authors.affiliation: Department of Chemistry, University of Utrecht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Kaptein
authors.forename: R M
authors.initials: RM
authors.lastname: Lamerichs
authors.forename: R
authors.initials: R
authors.lastname: Boelens
authors.forename: J A
authors.initials: JA
authors.lastname: Rullmann
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D004247:DNA / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009875:Operator Regions, Genetic; D010363:Pattern Recognition, Automated; D010446:Peptide Fragments / Q000378:metabolism; D011487:Protein Conformation; D012097:Repressor Proteins / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA