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GC ends control topology of DNA G-quadruplexes and their cation-dependent assembly.

ABSTRACT: GCn and GCnCG, where n = (G2AG4AG2), fold into well-defined, dimeric G-quadruplexes with unprecedented folding topologies in the presence of Na+ ions as revealed by nuclear magnetic resonance spectroscopy. Both G-quadruplexes exhibit unique combination of structural elements among which are two G-quartets, A(GGGG)A hexad and GCGC-quartet. Detailed structural characterization uncovered the crucial role of 5'-GC ends in formation of GCn and GCnCG G-quadruplexes. Folding in the presence of 15NH4+ and K+ ions leads to 3'-3' stacking of terminal G-quartets of GCn G-quadruplexes, while 3'-GC overhangs in GCnCG prevent dimerization. Results of the present study expand repertoire of possible G-quadruplex structures. This knowledge will be useful in DNA sequence design for nanotechnological applications that may require specific folding topology and multimerization properties.

SUBMITTER: Pavc D

PROVIDER: S-EPMC7049726 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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GC ends control topology of DNA G-quadruplexes and their cation-dependent assembly.

Pavc Daša D Wang Baifan B Spindler Lea L Drevenšek-Olenik Irena I Plavec Janez J Šket Primož P

Nucleic acids research 20200301 5

GCn and GCnCG, where n = (G2AG4AG2), fold into well-defined, dimeric G-quadruplexes with unprecedented folding topologies in the presence of Na+ ions as revealed by nuclear magnetic resonance spectroscopy. Both G-quadruplexes exhibit unique combination of structural elements among which are two G-quartets, A(GGGG)A hexad and GCGC-quartet. Detailed structural characterization uncovered the crucial role of 5'-GC ends in formation of GCn and GCnCG G-quadruplexes. Folding in the presence of 15NH4+ a ...[more]

PMID: 31996902

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