Thermodynamically stable and genetically unstable G-quadruplexes are depleted in genomes across species.

ABSTRACT: G-quadruplexes play various roles in multiple biological processes, which can be positive when a G4 is involved in the regulation of gene expression or detrimental when the folding of a stable G4 impairs DNA replication promoting genome instability. This duality interrogates the significance of their presence within genomes. To address the potential biased evolution of G4 motifs, we analyzed their occurrence, features and polymorphisms in a large spectrum of species. We found extreme bias of the short-looped G4 motifs, which are the most thermodynamically stable in vitro and thus carry the highest folding potential in vivo. In the human genome, there is an over-representation of single-nucleotide-loop G4 motifs (G4-L1), which are highly conserved among humans and show a striking excess of

SUBMITTER: Puig Lombardi E 

PROVIDER: S-EPMC6614823 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature