title: Suppression of DNA-mediated charge transport by BamHI binding.
abstract: A guanine radical cation produced by one-electron DNA oxidation migrates over long distances through the DNA pi-stack. Fundamental questions regarding the likelihood of charge transport in genomic DNA, the effects of protein binding, and its biological consequences arise as the next issues of study. Electronic effects of protein binding on the efficiency of charge transport were investigated for the endonuclease BamHI-DNA complex. Direct contact of a positively charged guanidium group of BamHI to guanines in the recognition sequence 5'-GGATCC-3' completely suppressed one-electron oxidation of the guanine in the protein binding site and dramatically lowered the charge transport efficiency through the sequence. Electronically insulated guanines, by the hydrogen bonding contact of a guanidium group in BamHI, no longer function as a stepping stone in the charge transport through the DNA pi-stack.
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Faculty of Engineering, Kyoto University, Japan. nakatani@sbchem.kyoto-u.ac.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakatani
authors.forename: Chikara
authors.initials: C
authors.lastname: Dohno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ogawa
authors.forename: Isao
authors.initials: I
authors.lastname: Saito
mesh_terms: D020029:Base Pairing; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D015245:Deoxyribonuclease BamHI / Q000737:chemistry*; D004579:Electron Transport; D006147:Guanine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010084:Oxidation-Reduction
chemical_list: D006147:Guanine; D004247:DNA; D015245:Deoxyribonuclease BamHI