Crystal structure of four-stranded Oxytricha telomeric DNA

Nature. 1992 Mar 12;356(6365):126-31. doi: 10.1038/356126a0.


The sequence d(GGGGTTTTGGGG) from the 3' overhang of the Oxytricha telomere has been crystallized and its three-dimensional structure solved to 2.5 A resolution. The oligonucleotide forms hairpins, two of which join to make a four-stranded helical structure with the loops containing four thymine residues at either end. The guanine residues are held together by cyclic hydrogen bonding and an ion is located in the centre. The four guanine residues in each segment have a glycosyl conformation that alternates between anti and syn. There are two four-stranded molecules in the asymmetric unit showing that the structure has some intrinsic flexibility.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Chemical Phenomena
  • Chemistry, Physical
  • Crystallization
  • DNA / chemistry*
  • Molecular Sequence Data
  • Molecular Structure
  • Nucleic Acid Conformation
  • Oxytricha / genetics*
  • Telomere / ultrastructure
  • X-Ray Diffraction


  • DNA