title: An eclectic DNA structure adopted by human telomeric sequence under superhelical stress and low pH.
abstract: We have found, with the aid of 2-D gel electrophoresis, that double-stranded human telomeric repeat, (T2AG3)12.(C3TA2)12, being cloned within a plasmid, forms a protonated superhelically-induced structure. Experiments on chemical and enzymatic probing also indicate that the human telomeric repeats adopt an unusual structure. We have proposed an eclectic model for this structure in which four different elements coexist: a non-orthodox intramolecular triplex stabilized by the canonical protonated C.G*C+ base-triads and highly enriched by noncanonical base-triads; the intramolecular quadruplex formed by a portion of the G-rich strand; the single-stranded region encompassing a portion of the G-rich strand and, probably, the (C,A)-hairpin formed by a portion of the C-rich strand.
authors.affiliation: Institute of Molecular Genetics, M.M.Shemyakin Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow.
authors.forename: O N
authors.initials: ON
authors.lastname: Voloshin
authors.forename: A G
authors.initials: AG
authors.lastname: Veselkov
authors.forename: B P
authors.initials: BP
authors.lastname: Belotserkovskii
authors.forename: O N
authors.initials: ON
authors.lastname: Danilevskaya
authors.forename: M N
authors.initials: MN
authors.lastname: Pavlova
authors.forename: V N
authors.initials: VN
authors.lastname: Dobrynin
authors.forename: M D
authors.initials: MD
authors.lastname: Frank-Kamenetskii
mesh_terms: D001483:Base Sequence; D004278:DNA, Superhelical / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D006863:Hydrogen-Ion Concentration; D015335:Molecular Probes; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D016615:Telomere
chemical_list: D004278:DNA, Superhelical; D015335:Molecular Probes; D009838:Oligodeoxyribonucleotides