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Updated: Aug 7, 2026

Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
Published on: September 19, 2017
Specific interactions of distamycin with G-quadruplex DNA
Melanie J Cocco1, L A Hanakahi, Michael D Huber
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA. cocco@csb.yale.edu
Abstract:
Distamycin binds the minor groove of duplex DNA at AT-rich regions and has been a valuable probe of protein interactions with double-stranded DNA. We find that distamycin can also inhibit protein interactions with G-quadruplex (G4) DNA, a stable four-stranded structure in which the repeating unit is a G-quartet. Using NMR, we show that distamycin binds specifically to G4 DNA, stacking on the terminal G-quartets and contacting the flanking bases. These results demonstrate the utility of distamycin as a probe of G4 DNA-protein interactions and show that there are (at least) two distinct modes of protein-G4 DNA recognition which can be distinguished by sensitivity to distamycin.
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