Serendipitous Discovery of a Guanine-rich DNA Molecule with a Highly Stable Structure in Urea

Wenqing Zhang; Meng Liu; Christine Lee; Bruno J Salena; Yingfu Li

doi:10.1038/s41598-018-20248-w

Serendipitous Discovery of a Guanine-rich DNA Molecule with a Highly Stable Structure in Urea

Sci Rep. 2018 Jan 31;8(1):1935. doi: 10.1038/s41598-018-20248-w.

Authors

Wenqing Zhang¹, Meng Liu¹, Christine Lee², Bruno J Salena³, Yingfu Li⁴

Affiliations

¹ Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main St W, Hamilton, ON, L8S 4K1, Canada.
² Department of Pathology and Molecular Medicine, McMaster University, 1280 Main St W, Hamilton, L8S 4K1, ON, Canada.
³ Department of Medicine, McMaster University, 1280 Main St W, Hamilton, ON, L8S 4K1, Canada.
⁴ Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main St W, Hamilton, ON, L8S 4K1, Canada. liying@mcmaster.ca.

Abstract

We have made an accidental discovery of an unusual, single-stranded, guanine-rich DNA molecule that is capable of adopting a folded structure in 7 M urea (7MU) known to denature nucleic acid structures. The folding of this molecule requires Na⁺ and Mg²⁺ and the folded structure remains stable when subjected to denaturing (7MU) polyacrylamide gel electrophoresis. Results from sequence mutagenesis, DNA methylation, and circular dichroism spectroscopy studies suggest that this molecule adopts an intramolecular guanine-quadruplex structure with 5 layers of guanine tetrads. Our finding indicates that DNA has the ability to create extremely stable structural folds despite its limited chemical repertoire, making it possible to develop DNA-based systems for unconventional applications.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Base Sequence
G-Quadruplexes / drug effects*
Ions
Metals / pharmacology
Time Factors
Urea / pharmacology*

Substances

Ions
Metals
Urea