1D92

REFINED CRYSTAL STRUCTURE OF AN OCTANUCLEOTIDE DUPLEX WITH G.T MISMATCHED BASE-PAIRS

Summary for 1D92

• Entry DOI: 10.2210/pdb1d92/pdb
• Descriptor: DNA (5'-D(*GP*GP*GP*GP*CP*TP*CP*C)-3') (2 entities in total)
• Functional Keywords: a-dna, double helix, mismatched, dna
• Total number of polymer chains: 2
• Total formula weight: 4887.21

Authors

Hunter, W.N.,Kneale, G.,Brown, T.,Rabinovich, D.,Kennard, O. (deposition date: 1992-10-17, release date: 1993-07-15, Last modification date: 2024-02-07)

Primary citation

Hunter, W.N.,Kneale, G.,Brown, T.,Rabinovich, D.,Kennard, O.
Refined crystal structure of an octanucleotide duplex with G . T mismatched base-pairs.
J.Mol.Biol., 190:605-618, 1986

PubMed Abstract: Single crystal X-ray diffraction techniques have been used to determine the structure of the DNA octamer d(G-G-G-G-C-T-C-C) at a resolution of 2.25 A. The asymmetric unit consists of two strands coiled about each other to produce an A-type DNA helix. The double helix contains six G . C Watson-Crick base-pairs and two G . T mismatched base-pairs. The mismatches adopt a "wobble" type structure in which both bases retain their major tautomer forms. The double helix is able to accommodate this G . T pairing with little distortion of the overall helical conformation. Crystals of this octamer melt at a substantially lower temperature than do those of a related octamer also containing two G . T base-pairs. We attribute this destabilization to disruption of the hydration network around the mismatch site combined with changes in intermolecular packing. Full details are given of conformational parameters, base stacking, intermolecular contacts and hydration involving 52 solvent molecules.

PubMed: 3783714
DOI: 10.1016/0022-2836(86)90246-9

Experimental method

X-RAY DIFFRACTION (2.25 Å)