Specific interactions of distamycin with G-quadruplex DNA.
Cocco MJ, Hanakahi LA, Huber MD, Maizels N
Nucleic Acids Research (2003)
Category: DNA structure ¤ Added: Jul 15, 2003 ¤ Rating: ◊◊
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.