Authors:
S-TD Hsu, P Varnai, A Bugaut, AP Reszka, S Neidle, S Balasubramanian
Journal name: 
J Am Chem Soc
Citation info: 
131(37):13399-13409
Abstract: 
Guanine-rich DNA sequences with the ability to form quadruplex structures are enriched in the promoter regions of protein-coding genes, particularly those of proto-oncogenes. G-quadruplexes are structurally polymorphic and their folding topologies can depend on the sample conditions. We report here on a structural study using solution state NMR spectroscopy of a second G-quadruplex-forming motif (c-kit2) that has been recently identified in the promoter region of the c-kit oncogene. In the presence of potassium ions, c-kit2 exists as an ensemble of structures that share the same parallel-stranded propeller-type conformations. Subtle differences in structural dynamics have been identified using hydrogen-deuterium exchange experiments by NMR spectroscopy, suggesting the coexistence of at least two structurally similar but dynamically distinct substates, which undergo slow interconversion on the NMR timescale.
DOI: 
http://doi.org/10.1021/ja904007p
Research group: 
Balasubramanian Group
E-pub date: 
23 Sep 2009