RNA Guanine Quadruplex Invasion by Complementary and Homologous PNA Probes

摘要

DNA and RNA oligomers that contain multiple runs of consecutive guanine (G) nucleotides are capable of folding into stable secondary structures known as G-quadruplexes,wherein four Gs are hydrogen bonded together into a roughly square planar array.Stacking of these tetrads and coordination of metal ions at the center of the structure yield a G-quadruplex.This secondary structural motif is gaining increasing attention as evidence grows implicating G-quadruplexes in regulation of gene expression.For example,a DNA G-quadruplex is suspected to form upstream of the main promoter for the c-MYC oncogene and to function as a represser for transcription.Meanwhile,an RNA G-quadruplex is believed to regulate alternative splicing of the pre-mRNA coding for hTERT,the reverse transcriptase component of the enzyme telomerase.Thus,synthetic compounds that bind to G-quadruplexes could find significant applications as therapeutics or as probes for gene function.