A parallel stranded G-quadruplex composed of threose nucleic acid (TNA)

Jen Yu Liao, Irina Anosova, Saikat Bala, Wade Van Horn, John C. Chaput

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

G-rich sequences can adopt four-stranded helical structures, called G-quadruplexes, that self-assemble around monovalent cations like sodium (Na+) and potassium (K+). Whether similar structures can be formed from xeno-nucleic acid (XNA) polymers with a shorter backbone repeat unit is an unanswered question with significant implications on the fold space of functional XNA polymers. Here, we examine the potential for TNA (α-l-threofuranosyl nucleic acid) to adopt a four-stranded helical structure based on a planar G-quartet motif. Using native polyacrylamide gel electrophoresis (PAGE), circular dichroism (CD) and solution-state nuclear magnetic resonance (NMR) spectroscopy, we show that despite a backbone repeat unit that is one atom shorter than the backbone repeat unit found in DNA and RNA, TNA can self-assemble into stable G-quadruplex structures that are similar in thermal stability to equivalent DNA structures. However, unlike DNA, TNA does not appear to discriminate between Na+ and K+ ions, as G-quadruplex structures form equally well in the presence of either ion. Together, these findings demonstrate that despite a shorter backbone repeat unit, TNA is capable of self-assembling into stable G-quadruplex structures.

Original languageEnglish (US)
Article numbere22999
JournalBiopolymers
Volume107
Issue number3
DOIs
StatePublished - Mar 1 2017

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Keywords

  • quadruplex
  • synthetic genetics
  • xeno-nucleic acids

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Biomaterials
  • Organic Chemistry

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