Molecular Crowding Induces Telomere G‐Quadruplex Formation under Salt‐Deficient Conditions and Enhances its Competition with Duplex Formation

Impact of crowding: Molecular crowding with poly(ethylene glycol) (PEG) induces the formation of a G-quadruplex structure in the guanine-rich strand of telomeric DNA at a K+-ion concentration that is unable to induce G-quadruplex formation alone. The picture shows the folding and unfolding of the telomeric DNA, revealed by fluorescence resonance energy transfer (FRET), the efficiency of which is inversely dependent on the distance between the donor (D) and acceptor (A).