---
OA_type: closed access
_id: '21103'
abstract:
- lang: eng
  text: The structure of the decadeoxyribonucleotide d(GCATGCATGC) is presented at
    a resolution of 1.8 Å. The decamer adopts a novel double-folded structure in which
    the direction of progression of the backbone changes at the two thymine residues.
    Intra-strand stacking interactions (including an interaction between the endocylic
    O atom of a ribose moiety and the adjacent purine base), hydrogen bonds and cobalt-ion
    interactions stabilize the double-folded structure of the single strand. Two such
    double-folded strands come together in the crystal to form a dimer. Inter-strand
    Watson–Crick hydrogen bonds form four base pairs. This portion of the decamer
    structure is similar to that observed in other previously reported oligonucleotide
    structures and has been dubbed a `bi-loop'. Both the double-folded single-strand
    structure, as well as the dimeric bi-loop structure, serve as starting points
    to construct models for triplet-repeat DNA sequences, which have been implicated
    in many human diseases.
article_processing_charge: No
article_type: original
author:
- first_name: Arunachalam
  full_name: Thirugnanasambandam, Arunachalam
  last_name: Thirugnanasambandam
- first_name: Selvam
  full_name: Karthik, Selvam
  last_name: Karthik
- first_name: Pradeep K
  full_name: Mandal, Pradeep K
  id: 6a3def15-d4b4-11ef-9fa9-a24c1f545ec3
  last_name: Mandal
  orcid: 0000-0001-5996-956X
- first_name: Namasivayam
  full_name: Gautham, Namasivayam
  last_name: Gautham
citation:
  ama: 'Thirugnanasambandam A, Karthik S, Mandal PK, Gautham N. The novel double-folded
    structure of d(GCATGCATGC): A possible model for triplet-repeat sequences. <i>Acta
    Crystallographica Section D Structural Biology</i>. 2015;71(10):2119-2126. doi:<a
    href="https://doi.org/10.1107/s1399004715013930">10.1107/s1399004715013930</a>'
  apa: 'Thirugnanasambandam, A., Karthik, S., Mandal, P. K., &#38; Gautham, N. (2015).
    The novel double-folded structure of d(GCATGCATGC): A possible model for triplet-repeat
    sequences. <i>Acta Crystallographica Section D Structural Biology</i>. International
    Union of Crystallography. <a href="https://doi.org/10.1107/s1399004715013930">https://doi.org/10.1107/s1399004715013930</a>'
  chicago: 'Thirugnanasambandam, Arunachalam, Selvam Karthik, Pradeep K Mandal, and
    Namasivayam Gautham. “The Novel Double-Folded Structure of d(GCATGCATGC): A Possible
    Model for Triplet-Repeat Sequences.” <i>Acta Crystallographica Section D Structural
    Biology</i>. International Union of Crystallography, 2015. <a href="https://doi.org/10.1107/s1399004715013930">https://doi.org/10.1107/s1399004715013930</a>.'
  ieee: 'A. Thirugnanasambandam, S. Karthik, P. K. Mandal, and N. Gautham, “The novel
    double-folded structure of d(GCATGCATGC): A possible model for triplet-repeat
    sequences,” <i>Acta Crystallographica Section D Structural Biology</i>, vol. 71,
    no. 10. International Union of Crystallography, pp. 2119–2126, 2015.'
  ista: 'Thirugnanasambandam A, Karthik S, Mandal PK, Gautham N. 2015. The novel double-folded
    structure of d(GCATGCATGC): A possible model for triplet-repeat sequences. Acta
    Crystallographica Section D Structural Biology. 71(10), 2119–2126.'
  mla: 'Thirugnanasambandam, Arunachalam, et al. “The Novel Double-Folded Structure
    of d(GCATGCATGC): A Possible Model for Triplet-Repeat Sequences.” <i>Acta Crystallographica
    Section D Structural Biology</i>, vol. 71, no. 10, International Union of Crystallography,
    2015, pp. 2119–26, doi:<a href="https://doi.org/10.1107/s1399004715013930">10.1107/s1399004715013930</a>.'
  short: A. Thirugnanasambandam, S. Karthik, P.K. Mandal, N. Gautham, Acta Crystallographica
    Section D Structural Biology 71 (2015) 2119–2126.
date_created: 2026-01-29T21:56:58Z
date_published: 2015-10-01T00:00:00Z
date_updated: 2026-02-23T09:09:14Z
day: '01'
doi: 10.1107/s1399004715013930
extern: '1'
has_accepted_license: '1'
intvolume: '        71'
issue: '10'
language:
- iso: eng
month: '10'
oa_version: None
page: 2119-2126
publication: Acta Crystallographica Section D Structural Biology
publication_identifier:
  issn:
  - 1399-0047
publication_status: published
publisher: International Union of Crystallography
quality_controlled: '1'
status: public
title: 'The novel double-folded structure of d(GCATGCATGC): A possible model for triplet-repeat
  sequences'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 71
year: '2015'
...