title: Triplex formation involving 2',4'-BNA with 2-pyridone base analogue: efficient and selective recognition of C:G interruption.
abstract: We examined the thermodynamic properties of 2',4'-bridged nucleic acid containing 2-pyridone as a nucleobase (PB) to recognize a C interruption in the homopurine strand of the target duplex for pyrimidine motif triplex formation at neutral pH. The triplex formation involving triplex-forming oligonucleotide with PB is highly sequence-selective to specifically recognize C:G target base pair rather than the other G:C, T:A, or A:T base pairs. PB.C:G triad gives significantly larger binding constant than T.C:G triad, which has been known to be the most stable combination in natural base.C:G triad. Our results certainly support the idea that PB could be a key nucleoside to recognize a C interruption in the homopurine strand of the target duplex with high binding affinity and selectivity, and reduce the restriction of target sequences for triplex formation.
authors.affiliation: Institute of Physical and Chemical Research (RIKEN), 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Torigoe
authors.forename: Y
authors.initials: Y
authors.lastname: Hari
authors.forename: S
authors.initials: S
authors.lastname: Obika
authors.forename: T
authors.initials: T
authors.lastname: Imanishi
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry; D011728:Pyridones / Q000737:chemistry*; D011742:Pyrimidine Nucleotides / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D011728:Pyridones; D011742:Pyrimidine Nucleotides; C051802:triplex DNA; D006147:Guanine; C017679:2-hydroxypyridine; D003596:Cytosine; D004247:DNA