X-ray characterization of mesophases of human telomeric G-quadruplexes and other DNA analogues
- Univ. of Massachusetts, Amherst, MA (United States). Dept. of Physics
- Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Macromolecular Science and Engineering
- Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Macromolecular Science and Engineering, Dept. of Biomedical Engineering, Dept. of Radiology, Dept. of Materials Science and Engineering, Comprehensive Cancer Center, Div. of General Medical Sciences and Oncology
- Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Macromolecular Science and Engineering, Dept. of Biomedical Engineering, Dept. of Materials Science and Engineering, Dept. of Physics
- Univ. of Massachusetts, Amherst, MA (United States). Dept. of Physics; Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering; J. Stefan Institute, Ljubljana (Slovenia). Dept. of Theoretical Physics; Univ. of Ljubljana, Ljubljana (Slovenia). Dept. of Physics, Faculty of Mathematics and Physics
We report that observed in the folds of guanine-rich oligonucleotides, non-canonical G-quadruplex structures are based on G-quartets formed by hydrogen bonding and cation-coordination of guanosines. In dilute 5'-guanosine monophosphate (GMP) solutions, G-quartets form by the self-assembly of four GMP nucleotides. We use x-ray diffraction to characterize the columnar liquid-crystalline mesophases in concentrated solutions of various model G-quadruplexes. We then probe the transitions between mesophases by varying the PEG solution osmotic pressure, thus mimicking in vivo molecular crowding conditions. Using the GMP-quadruplex, built by the stacking of G-quartets with no covalent linking between them, as the baseline, we report the liquid-crystalline phase behaviors of two other related G-quadruplexes: (i) the intramolecular parallel-stranded G-quadruplex formed by the 22-mer four-repeat human telomeric sequence AG3 (TTAG3)3 and (ii) the intermolecular parallel-stranded G-quadruplex formed by the TG(4)T oligonucleotides. Finally, we compare the mesophases of the G-quadruplexes, under PEG-induced crowding conditions, with the corresponding mesophases of the canonical duplex and triplex DNA analogues.
- Research Organization:
- 10.1038/srep27079
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Division of Materials Sciences and Engineering
- Grant/Contract Number:
- SC0008176; SC0008068
- OSTI ID:
- 1280920
- Journal Information:
- Scientific Reports, Vol. 6; ISSN 2045-2322
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Molecular Dynamics Simulation of High Density DNA Arrays
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journal | January 2018 |
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