1EL2

SOLUTION STRUCTURE OF A MODIFIED HUMAN TELOMERE FRAGMENT (STRUCTURE "A")


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 
  • Selection Criteria: structures with the least restraint violations, structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The solution structure and internal motions of a fragment of the cytidine-rich strand of the human telomere.

Phan, A.T.Gueron, M.Leroy, J.L.

(2000) J.Mol.Biol. 299: 123-144

  • DOI: 10.1006/jmbi.2000.3613
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • We present the solution structure of d(CCCTA2CCCTA2CCCTA2CCCT), a fragment of the vertebrate telomere which folds intramolecularly. The four cytidine stretches form an i-motif which includes six intercalated C.C+ pairs and terminates with the cytidin ...

    We present the solution structure of d(CCCTA2CCCTA2CCCTA2CCCT), a fragment of the vertebrate telomere which folds intramolecularly. The four cytidine stretches form an i-motif which includes six intercalated C.C+ pairs and terminates with the cytidines at the 5' extremity of each stretch. Above, the second TA2 linker loops across one of the narrow grooves, while at the bottom, the first and third linkers loop across the wide grooves. At 30 degrees C, the spectra of the first and third linkers are quasi-degenerate. Severe broadening at lower temperature indicates that this results from motional averaging between at least two structures of each bottom loop, and makes it impossible to solve the configuration of the bottom loops directly, in contrast to the rest of the structure. We therefore turned to the modified sequence d(CCCTA(2)5MCCCTA2CCCUA2CCCT) in which the two base substitutions (underlined) break the quasi-symmetry between linkers 1 and 3. The three loops follow approximately the hairpin "second pattern" of Hilbers. In the first loop, T4 is in the syn orientation, whereas its analog in the third loop, U16, oriented anti, is in a central location, where it interacts with bases of both loops, thus contributing to their tight association. The only motion is a syn/anti flip of A18 in the third loop. Returning to the telomere fragment, we show that each of the bottom loops switches between the structures identified in the first and third loops of the modified structure. The motions are concerted, and the resulting configurations of the bottom loop cluster present a bulge to either right (T4 syn) or left (T16 syn).


    Organizational Affiliation

    Groupe de Biophysique de l'Ecole Polytechnique, et de l'UMR 7643 du CNRS 91128 Palaiseau, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
5'-D(*CP*CP*CP*TP*AP*AP*(5CM)P*CP*CP*TP*AP*AP*CP*CP*CP*UP*AP*AP*CP*CP*CP*T)-3'A22N/A
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
5CM
Query on 5CM
A
DNA LINKINGC10 H16 N3 O7 PDC
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 
  • Selection Criteria: structures with the least restraint violations, structures with the lowest energy 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-03-27
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance