These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Evidence for crystal environment dominating base sequence effects on DNA conformation: crystal structures of the orthorhombic and hexagonal polymorphs of the A-DNA decamer d(GCGGGCCCGC) and comparison with their isomorphous crystal structures.
    Author: Ramakrishnan B, Sundaralingam M.
    Journal: Biochemistry; 1993 Oct 26; 32(42):11458-68. PubMed ID: 8218212.
    Abstract:
    We have determined the structure of the A-DNA decamer d(GCGGGCCCGC) in two crystal forms, orthorhombic and hexagonal, at 1.7- and 1.8-A resolution, respectively. In the orthorhombic form, the fifth guanine residue has nearly trans-trans conformations for the alpha-gamma backbone torsions, as in the isomorphous orthorhombic structure d(CCCGGCCGGG) [Ramakrishnan, B., & Sundaralingam, M. (1993) J. Mol. Biol. 231, 431-444]. However, in the hexagonal form, the eighth cytosine residue adopts the trans-trans conformations for the backbone alpha-gamma torsions, as in the isomorphous hexagonal structure d(ACCGGCCGGT) [Frederick, C. A., Quigley, G. J., Teng, M.-K., Coll, M., van der Marel, G. A., van Boom, J. H., Rich, A., & Wang, A. H.-J. (1989) Eur. J. Biochem. 181, 295-307]. Even though the average helix and base-pair parameters are nearly the same in the two polymorphous crystal forms having the same sequence, many of the base-dependent local helix parameters are quite different. However, in the isomorphous crystal forms, in spite of the differing base sequences, the local helix and base-pair parameters of the duplexes are nearly the same. This indicates that, in crystals, the local conformation of a DNA structure is affected severely by the crystal packing environment rather than by the base sequence.
    [Abstract] [Full Text] [Related] [New Search]