Conserved elements with potential to form polymorphic G-quadruplex structures in the first intron of human genes.

ABSTRACT: To understand how potential for G-quadruplex formation might influence regulation of gene expression, we examined the 2 kb spanning the transcription start sites (TSS) of the 18 217 human RefSeq genes, distinguishing contributions of template and nontemplate strands. Regions both upstream and downstream of the TSS are G-rich, but the downstream region displays a clear bias toward G-richness on the nontemplate strand. Upstream of the TSS, much of the G-richness and potential for G-quadruplex formation derives from the presence of well-defined canonical regulatory motifs in duplex DNA, including CpG dinucleotides which are sites of regulatory methylation, and motifs recognized by the transcription factor SP1. This challenges the notion that quadruplex formation upstream of the TSS contribute

SUBMITTER: Eddy J 

PROVIDER: S-EPMC2275096 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature