A G-rich sequence within the c-kit oncogene promoter forms a parallel G-quadruplex having asymmetric G-tetrad dynamics.
J Am Chem Soc
; 131(37): 13399-409, 2009 Sep 23.
Article
em En
| MEDLINE
| ID: mdl-19705869
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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Regiões Promotoras Genéticas
/
Proteínas Proto-Oncogênicas c-kit
/
Sequência Rica em GC
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Quadruplex G
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Reino Unido