Solution structure of the major G-quadruplex formed in the human VEGF promoter in K+: insights into loop interactions of the parallel G-quadruplexes.

ABSTRACT: Vascular endothelial growth factor (VEGF) proximal promoter region contains a poly G/C-rich element that is essential for basal and inducible VEGF expression. The guanine-rich strand on this tract has been shown to form the DNA G-quadruplex structure, whose stabilization by small molecules can suppress VEGF expression. We report here the nuclear magnetic resonance structure of the major intramolecular G-quadruplex formed in this region in K(+) solution using the 22mer VEGF promoter sequence with G-to-T mutations of two loop residues. Our results have unambiguously demonstrated that the major G-quadruplex formed in the VEGF promoter in K(+) solution is a parallel-stranded structure with a 1:4:1 loop-size arrangement. A unique capping structure was shown to form in this 1:4:1 G-quadruplex. P

SUBMITTER: Agrawal P 

PROVIDER: S-EPMC3905851 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature