2MBJ

Structure of an antiparallel (2+2) G-quadruplex formed by human telomeric repeats in Na+ solution (with G22-to-BrG substitution)

Summary for 2MBJ

• Entry DOI: 10.2210/pdb2mbj/pdb
• Related: 143D 1KF1 2JSL 2JSM 2KF8
• NMR Information: BMRB: 19402
• Descriptor: DNA_(27-MER) (1 entity in total)
• Functional Keywords: anticancer targets, g-quadruplex, human telomere, dna
• Total number of polymer chains: 1
• Total formula weight: 8592.37

Authors

Lim, K.W.,Ng, V.C.M.,Martin-Pintado, N.,Heddi, B.,Phan, A.T. (deposition date: 2013-08-02, release date: 2013-09-18, Last modification date: 2024-05-15)

Primary citation

Lim, K.W.,Ng, V.C.,Martin-Pintado, N.,Heddi, B.,Phan, A.T.
Structure of the human telomere in Na+ solution: an antiparallel (2+2) G-quadruplex scaffold reveals additional diversity.
Nucleic Acids Res., 41:10556-10562, 2013

PubMed Abstract: Single-stranded DNA overhangs at the ends of human telomeric repeats are capable of adopting four-stranded G-quadruplex structures, which could serve as potential anticancer targets. Out of the five reported intramolecular human telomeric G-quadruplex structures, four were formed in the presence of K(+) ions and only one in the presence of Na(+) ions, leading often to a perception that this structural polymorphism occurs exclusively in the presence of K(+) but not Na(+). Here we present the structure of a new antiparallel (2+2) G-quadruplex formed by a derivative of a 27-nt human telomeric sequence in Na(+) solution, which comprises a novel core arrangement distinct from the known topologies. This structure complements the previously elucidated basket-type human telomeric G-quadruplex to serve as reference structures in Na(+)-containing environment. These structures, together with the coexistence of other conformations in Na(+) solution as observed by nuclear magnetic resonance spectroscopy, establish the polymorphic nature of human telomeric repeats beyond the influence of K(+) ions.

PubMed: 23999095
DOI: 10.1093/nar/gkt771

Experimental method

SOLUTION NMR