title: Stacking of G-quadruplexes: NMR structure of a G-rich oligonucleotide with potential anti-HIV and anticancer activity.
abstract: G-rich oligonucleotides T30695 (or T30923), with the sequence of (GGGT)(4), and T40214, with the sequence of (GGGC)(4), have been reported to exhibit anti-HIV and anticancer activity. Here we report on the structure of a dimeric G-quadruplex adopted by a derivative of these sequences in K(+) solution. It comprises two identical propeller-type parallel-stranded G-quadruplex subunits each containing three G-tetrad layers that are stacked via the 5'-5' interface. We demonstrated control over the stacking of the two monomeric subunits by sequence modifications. Our analysis of possible structures at the stacking interface provides a general principle for stacking of G-quadruplexes, which could have implications for the assembly and recognition of higher-order G-quadruplex structures.
authors.affiliation: School of Physical and Mathematical Sciences and School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Ngoc Quang
authors.initials: NQ
authors.lastname: Do
authors.forename: Kah Wai
authors.initials: KW
authors.lastname: Lim
authors.forename: Ming Hoon
authors.initials: MH
authors.lastname: Teo
authors.forename: Brahim
authors.initials: B
authors.lastname: Heddi
authors.forename: Anh Tuân
authors.initials: AT
authors.lastname: Phan
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry; D019427:HIV Integrase / Q000378:metabolism; D019428:HIV Integrase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D007288:Inosine / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009841:Oligonucleotides / Q000737:chemistry* / Q000494:pharmacology; D011188:Potassium / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D019428:HIV Integrase Inhibitors; D009841:Oligonucleotides; D007288:Inosine; D006147:Guanine; D019427:HIV Integrase; D011188:Potassium; C514801:p31 integrase protein, Human immunodeficiency virus 1