2hy9
From Proteopedia
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solution structure of the human telomeric quadruplex
Overview
We report the NMR solution structure of the intramolecular G-quadruplex, formed in human telomeric DNA in K(+). The hybrid-type telomeric, G-quadruplex consists of three G-tetrads linked with mixed, parallel-antiparallel G-strands, with the bottom two G-tetrads having the, same G-arrangement (anti:anti:syn:anti) and the top G-tetrad having the, reversed G-arrangement (syn:syn:anti:syn). The three TTA loop segments, adopt different conformations, with the first TTA assuming a, double-chain-reversal loop conformation, and the second and third TTA, assuming lateral loop conformations. The NMR structure is very well, defined, including the three TTA loops and the two flanking sequences at, 5'- and 3'-ends. Our study indicates that the three loop regions interact, with the core G-tetrads in a specific way that defines and stabilizes the, unique human telomeric G-quadruplex structure in K(+). Significantly, a, novel adenine triple platform is formed with three naturally occurring, adenine residues, A21, A3 and A9, capping the top tetrad of the, hybrid-type telomeric G-quadruplex. This adenine triple is likely to play, an important role in the formation of a stable human telomeric, G-quadruplex structure in K(+). The unique human telomeric G-quadruplex, structure formed in K(+) suggests that it can be specifically targeted for, anticancer drug design.
About this Structure
2HY9 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Structure of the intramolecular human telomeric G-quadruplex in potassium solution: a novel adenine triple formation., Dai J, Punchihewa C, Ambrus A, Chen D, Jones RA, Yang D, Nucleic Acids Res. 2007;35(7):2440-50. Epub 2007 Mar 29. PMID:17395643
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