2KF8

Structure of a two-G-tetrad basket-type intramolecular G-quadruplex formed by human telomeric repeats in K+ solution


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 10 
  • Conformers Submitted: 10 
  • Selection Criteria: all calculated structures submitted 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure of the human telomere in K+ solution: a stable basket-type G-quadruplex with only two G-tetrad layers

Lim, K.W.Amrane, S.Bouaziz, S.Xu, W.Mu, Y.Patel, D.J.Luu, K.N.Phan, A.T.

(2009) J.Am.Chem.Soc. 131: 4301-4309

  • DOI: 10.1021/ja807503g
  • Primary Citation of Related Structures:  2KF7

  • PubMed Abstract: 
  • Previously, it has been reported that human telomeric DNA sequences could adopt in different experimental conditions four different intramolecular G-quadruplexes each involving three G-tetrad layers, namely, Na(+) solution antiparallel-stranded baske ...

    Previously, it has been reported that human telomeric DNA sequences could adopt in different experimental conditions four different intramolecular G-quadruplexes each involving three G-tetrad layers, namely, Na(+) solution antiparallel-stranded basket form, K(+) crystal parallel-stranded propeller form, K(+) solution (3 + 1) Form 1, and K(+) solution (3 + 1) Form 2. Here we present a new intramolecular G-quadruplex adopted by a four-repeat human telomeric sequence in K(+) solution (Form 3). This structure is a basket-type G-quadruplex with only two G-tetrad layers: loops are successively edgewise, diagonal, and edgewise; glycosidic conformations of guanines are syn x syn x anti x anti around each tetrad. Each strand of the core has both a parallel and an antiparallel adjacent strands; there are one narrow, one wide, and two medium grooves. Despite the presence of only two G-tetrads in the core, this structure is more stable than the three-G-tetrad intramolecular G-quadruplexes previously observed for human telomeric sequences in K(+) solution. Detailed structural elucidation of Form 3 revealed extensive base pairing and stacking in the loops capping both ends of the G-tetrad core, which might explain the high stability of the structure. This novel structure highlights the conformational heterogeneity of human telomeric DNA. It establishes a new folding principle for G-quadruplexes and suggests new loop sequences and structures for targeting in human telomeric DNA.


    Organizational Affiliation

    School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
HUMAN TELOMERE DNAA22N/A
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 10 
  • Conformers Submitted: 10 
  • Selection Criteria: all calculated structures submitted 

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-03-24
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance