Conformational heterogeneity in a fully-complementary DNA three-way junction with a GC-rich branchpoint

Magennis, S. , Toulmin, A., Baltierra-Jasso, L. E., Morten, M. J., Sabir, T., McGlynn, P., Schröder, G. F., Smith, B. O. and Magennis, S. W. (2017) Conformational heterogeneity in a fully-complementary DNA three-way junction with a GC-rich branchpoint. Biochemistry, 56(37), pp. 4985-4991. (doi: 10.1021/acs.biochem.7b00677) (PMID:28820590)

Abstract

DNA three-way junctions (3WJs) are branched structures that serve as important biological intermediates and as components in DNA nanostructures. We recently derived the global structure of a fully-complementary 3WJ and found that it contained unpaired bases at the branchpoint, in support of previous observations of branch flexibility and branchpoint reactivity. By combining high-resolution single-molecule FRET, molecular modeling, time-resolved ensemble fluorescence spectroscopy and the first 19F NMR observations of fully complementary 3WJs, we now show that the 3WJ structure can adopt multiple distinct conformations depending upon the sequence at the branchpoint. A 3WJ with a GC-rich branchpoint adopts an open conformation with unpaired bases at the branch and at least one additional conformation with increased base interactions at the branchpoint. This structural diversity has implications for branch interactions and processing in vivo and for technological applications.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Magennis, Dr Steven and Morten, Dr Michael and Smith, Dr Brian
• Authors: Magennis, S., Toulmin, A., Baltierra-Jasso, L. E., Morten, M. J., Sabir, T., McGlynn, P., Schröder, G. F., Smith, B. O., and Magennis, S. W.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences; College of Science and Engineering > School of Chemistry
• Journal Name: Biochemistry
• Publisher: American Chemical Society
• ISSN: 0006-2960
• ISSN (Online): 1520-4995
• Published Online: 18 August 2017
• Copyright Holders: Copyright © 2017 American Chemical Society
• First Published: First published in Biochemistry 56(37): 4985-4991
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
65718	1	From nature to nano: structure, dynamics and reactivity of DNA three-way junctions	Steven Magennis	Engineering and Physical Sciences Research Council (EPSRC)	EP/L027003/1	SCHOOL OF CHEMISTRY