G-quadruplexes with (4n - 1) guanines in the G-tetrad core: formation of a G-triad·water complex and implication for small-molecule binding.

ABSTRACT: G-quadruplexes are non-canonical structures of nucleic acids, in which guanine bases form planar G-tetrads (G·G·G·G) that stack on each other in the core of the structure. G-quadruplexes generally contain multiple times of four (4n) guanines in the core. Here, we study the structure of G-quadruplexes with only (4n - 1) guanines in the core. The solution structure of a DNA sequence containing 11 guanines showed the formation of a parallel G-quadruplex involving two G-tetrads and one G-triad with a vacant site. Molecular dynamics simulation established the formation of a stable G-triad·water complex, where water molecules mimic the position of the missing guanine in the vacant site. The concept of forming G-quadruplexes with missing guanines in the core broadens the current definition of G-q

SUBMITTER: Heddi B 

PROVIDER: S-EPMC4737152 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature