1d90

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Template:STRUCTURE 1d90

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

Overview

The structure of the synthetic deoxyoctamer d(GGIGCTCC) has been determined by single crystal X-ray diffraction techniques to a resolution of 1.7A. The sequence crystallises in space group P6(1), with unit cell dimensions a = b = 45.07, c = 45.49A. The refinement converged with a crystallographic residual R = 0.14 and the location of 81 solvent molecules. The octamer forms an A-DNA duplex with 6 Watson-Crick (G.C) base pairs and 2 inosine-thymine (I.T) pairs. Refinement of the structure shows it to be essentially isomorphous with that reported for d(GGGGCTCC) with the mispairs adopting a "wobble" conformation. Conformational parameters and base stacking interactions are compared to those for the native duplex d(GGGGCCCC) and other similar sequences. A rationale for the apparent increased crystal packing efficiency and lattice stability of the I.T octamer is given.

About this Structure

Full crystallographic information is available from OCA.

Reference

Refined crystal structure of an octanucleotide duplex with I.T. mismatched base pairs., Cruse WB, Aymani J, Kennard O, Brown T, Jack AG, Leonard GA, Nucleic Acids Res. 1989 Jan 11;17(1):55-72. PMID:2911488 Page seeded by OCA on Fri May 2 13:35:08 2008