title: Coupling sequence-specific recognition to DNA modification.
abstract: Enzymes that modify DNA are faced with significant challenges in specificity for both substrate binding and catalysis. We describe how single hydrogen bonds between M.HhaI, a DNA cytosine methyltransferase, and its DNA substrate regulate the positioning of a peptide loop which is approximately 28 A away. Stopped-flow fluorescence measurements of a tryptophan inserted into the loop provide real-time observations of conformational rearrangements. These long-range interactions that correlate with substrate binding and critically, enzyme turnover, will have broad application to enzyme specificity and drug design for this medically relevant class of enzymes.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
authors.forename: R August
authors.initials: RA
authors.lastname: Estabrook
authors.forename: Trung T
authors.initials: TT
authors.lastname: Nguyen
authors.forename: Nickolas
authors.initials: N
authors.lastname: Fera
authors.forename: Norbert O
authors.initials: NO
authors.lastname: Reich
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D015257:DNA-Cytosine Methylases / Q000737:chemistry* / Q000378:metabolism*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011485:Protein Binding; D013050:Spectrometry, Fluorescence
chemical_list: D004247:DNA; D015257:DNA-Cytosine Methylases