title: Zinc destabilizes DNA Watson-Crick pairs at AGCT.
abstract: Zinc, a component of a large number of enzymes and an abundant and essential trace metal, alters the structure of AGCT sites in negatively supercoiled DNA. Related sequences show little or no effect. Cobalt and cadmium show reactivities similar to zinc. The conformational change in DNA was fine mapped with haloacetaldehydes using chemical cleavage or primer extension methods. Since a many fold excess of zinc to AGCT sites is required to saturate the reaction, we propose that the zinc-AGT complex is preferentially accessible to the haloacetaldehyde probes due to a conformational deformation. Hence, zinc is the smallest ligand (by approximately 500-fold) that causes a perturbation of a specific DNA sequence.
authors.affiliation: Institute of Biosciences and Technology, Texas A & M University, Texas Medical Center, Houston 77030.
authors.forename: S
authors.initials: S
authors.lastname: Kang
authors.forename: R D
authors.initials: RD
authors.lastname: Wells
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D002104:Cadmium / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology; D004278:DNA, Superhelical / Q000737:chemistry* / Q000187:drug effects; D008274:Magnesium / Q000494:pharmacology; D008961:Models, Structural; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry* / Q000187:drug effects; D015032:Zinc / Q000494:pharmacology*; D017967:Zinc Compounds / Q000494:pharmacology
chemical_list: D002712:Chlorides; D004278:DNA, Superhelical; D017967:Zinc Compounds; D002104:Cadmium; D003035:Cobalt; C016837:zinc chloride; D008274:Magnesium; D015032:Zinc