1kbd: Difference between revisions

[[Image:1kbd.gif|left|200px]]

'''SOLUTION STRUCTURE OF A 16 BASE-PAIR DNA RELATED TO THE HIV-1 KAPPA B SITE'''

1H and 31P NMR spectroscopy have been used together with molecular modelling to determine the fine structure of a non-palindromic 16 bp DNA containing the NF-kappa B binding site. Much emphasis has been placed upon NMR optimization of both two-dimensional 31P NMR techniques to extract structural information defining the phosphodiester backbone conformation and selective homonuclear 2D COSY experiments to determine sugar conformations. NMR data show evidence for a dynamic behaviour of steps flanking the ten base-pairs of the NF-kappa B binding site. A BI-BII equilibrium at these steps is demonstrated and two models for each extreme conformation are proposed in agreement with NMR data. In the refined BII structures, the NF-kappa B binding site exhibits an intrinsic curvature towards the major groove that is magnified by the four flanking steps in the BII conformation. Furthermore, the base-pairs are translated into the major groove. Thus, we present a novel mode of dynamic intrinsic curvature compatible with the DNA curvature observed in the X-ray structure of the p50-DNA complex.

Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KBD OCA].  

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