title: Self-association of cyclic oligonucleotides through G:T:G:T minor groove tetrads.
abstract: Minor groove aligned tetrads resulting from the association of Watson-Crick base pairs stabilize a distinct class of four-stranded DNA structures, different from G-quadruplexes or i-motifs. These tetrads can be formed by several arrangements of G-C or A-T base pairs. Here we prove that minor groove tetrads can be also formed by G-T mismatches. In this manuscript we describe the dimeric solution structures of two cyclic oligonucleotides stabilized by intermolecular G-T non-canonical base pairs. In the dimeric structure of d<pTCGTATGT>, these mismatches interact to each other giving rise to minor groove aligned G:T:G:T or mixed G:T:G:C tetrads. Interestingly, the stability conferred by mismatched G-T containing tetrads is similar to that of minor groove tetrads solely formed by G-C Watson-Crick base pairs.
authors.affiliation: Departament de Química Orgànica, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Júlia
authors.initials: J
authors.lastname: Viladoms
authors.forename: Núria
authors.initials: N
authors.lastname: Escaja
authors.forename: Enrique
authors.initials: E
authors.lastname: Pedroso
authors.forename: Carlos
authors.initials: C
authors.lastname: González
mesh_terms: D020029:Base Pairing; D019281:Dimerization; D054856:G-Quadruplexes; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry*
chemical_list: D009841:Oligonucleotides