Sugar Puckering Drives G-Quadruplex Refolding: Implications for V-Shaped Loops.

ABSTRACT: A DNA G-quadruplex adopting a (3+1) hybrid structure was modified in two adjacent syn positions of the antiparallel strand with anti-favoring 2'-deoxy-2'-fluoro-riboguanosine (^F rG) analogues. The two substitutions promoted a structural rearrangement to a topology with the 5'-terminal G residue located in the central tetrad and the two modified residues linked by a V-shaped zero-nucleotide loop. Strikingly, whereas a sugar pucker in the preferred north domain is found for both modified nucleotides, the ^F rG analogue preceding the V-loop is forced to adopt the unfavored syn conformation in the new quadruplex fold. Apparently, a preferred C3'-endo sugar pucker within the V-loop architecture outweighs the propensity of the ^F rG analogue to adopt an anti glycos

SUBMITTER: Haase L 

PROVIDER: S-EPMC6973071 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature