title: The selective B-A conformational transition of the central dinucleotide (CpG) segment of d(CAATCCGGATTG)2 induced by delta-Co(en)3(3+).
abstract: The binding of Co(NH3)6(3+), delta-Co(en)3(3+) and delta-Rh(en)3(3+) to the dodecanucleotide d(CAATCCGGATTG)2 has been studied by 1H NMR. Addition of Co(NH3)6(3+), delta-Co(en)3(3+) or delta-Rh(en)3(3+) to d(CAATCCGGATTG)2 induce a similar pattern of chemical shift movements of the dodecanucleotide base protons. Analysis of the chemical shift changes as a function of added metal-ion complex shows that the binding affinity for d(CAATCCGGATTG)2 decreases in the order: delta-Co(en)3(3+) > delta-Rh(en)3(3+) > Co(NH3)6(3+). Addition of a saturating ratio of delta-Co(en)3(3+) to d(CAATCCGGATTG)2 induces a selective B to A type-DNA transition for the central CpG segment of the dodecanucleotide, with all other nucleotide residues maintaining the B-type conformation.
authors.affiliation: Department of Chemistry, University of New South Wales, Australia.
authors.forename: T A
authors.initials: TA
authors.lastname: Watt
authors.forename: C
authors.initials: C
authors.lastname: Tong
authors.forename: A P
authors.initials: AP
authors.lastname: Arnold
authors.forename: J G
authors.initials: JG
authors.lastname: Collins
mesh_terms: D001483:Base Sequence; D003035:Cobalt / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D015226:Dinucleoside Phosphates / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003035:Cobalt; D004247:DNA; D015226:Dinucleoside Phosphates; D005029:Ethylenediamines; D009838:Oligodeoxyribonucleotides; D009942:Organometallic Compounds; C096699:tris(ethylenediamine)cobalt(III); C015772:CpG dinucleotide