User:MichaelChiorazzo/sandbox

Telomeric repeats in a variety of organisms have been shown to form these quadruplex structures in vitro, and subsequently they have also been shown to form in vivo. The human telomeric repeat (which is the same for all vertebrates) consists of many repeats of the sequenced (GGTTAG), and the quadruplexes formed by this structure have been well studied by NMR and X-ray crystal structure determination. The formation of these quadruplexes in telomeres has been shown to decrease the activity of the enzyme telomerase, which is responsible for maintaining length of telomeres and is involved in around 85% of all cancers. This is an active target of drug discovery, including telomestatin.