title: Complex structural behavior of oligopurine-oligopyrimidine sequence cloned within the supercoiled plasmid.
abstract: Synthetic sequence GATCC(AG)7ATCG(AT)4CG(AG)7 was cloned into plasmid and its structural behavior under the influence of supercoiling was analysed by chemical modification at variety of experimental conditions. It was found that this sequence adopts at least two different non-B conformations depending on -delta and pH values. Moreover, 12 nucleotide long non-pur.pyr spacer region separating two identical (AG)7 blocks does not provide a significant energy barrier protecting against unusual structures formation.
authors.affiliation: Department of Bioorganic Chemistry, Polish Academy of Sciences, Lodz.
authors.forename: P
authors.initials: P
authors.lastname: Parniewski
authors.forename: G
authors.initials: G
authors.lastname: Galazka
authors.forename: A
authors.initials: A
authors.lastname: Wilk
authors.forename: J
authors.initials: J
authors.lastname: Klysik
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004278:DNA, Superhelical; D004047:Diethyl Pyrocarbonate; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D009710:Nucleotide Mapping; D009993:Osmium Tetroxide; D010957:Plasmids; D011684:Purine Nucleosides; D011741:Pyrimidine Nucleosides; D013329:Structure-Activity Relationship
chemical_list: D004278:DNA, Superhelical; D011684:Purine Nucleosides; D011741:Pyrimidine Nucleosides; D004047:Diethyl Pyrocarbonate; D009993:Osmium Tetroxide