title: HIV-1 integrase inhibitor T30177 forms a stacked dimeric G-quadruplex structure containing bulges.
abstract: T30177 is a G-rich oligonucleotide with the sequence (GTGGTGGGTGGGTGGGT) which inhibits the HIV-1 integrase activity at nanomolar concentrations. Here we show that this DNA sequence forms in K(+) solution a dimeric G-quadruplex structure comprising a total of six G-tetrad layers through the stacking of two propeller-type parallel-stranded G-quadruplex subunits at their 5'-end. All twelve guanines in the sequence participate in the G-tetrad formation, despite the interruption in the first G-tract by a thymine, which forms a bulge between two adjacent G-tetrads. In this work, we also propose a simple analytical approach to stoichiometry determination using concentration-dependent melting curves.
authors.affiliation: School of Physical and Mathematical Sciences and School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Vineeth Thachappilly
authors.initials: VT
authors.lastname: Mukundan
authors.forename: Ngoc Quang
authors.initials: NQ
authors.lastname: Do
authors.forename: Anh Tuân
authors.initials: AT
authors.lastname: Phan
mesh_terms: D019281:Dimerization; D054856:G-Quadruplexes; D019427:HIV Integrase; D019428:HIV Integrase Inhibitors / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009841:Oligonucleotides / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry
chemical_list: D019428:HIV Integrase Inhibitors; D009841:Oligonucleotides; C098172:T 30177; D019427:HIV Integrase; D011188:Potassium; C514801:p31 integrase protein, Human immunodeficiency virus 1