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378d
From Proteopedia
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STRUCTURE OF THE SIDE-BY-SIDE BINDING OF DISTAMYCIN TO DNA
Overview
The 2.40 A resolution crystal structure of a side-by-side binding of, distamycin A molecules to a DNA octamer d(GTATATAC)2 with an extended, alternating TA sequence has been determined. The unit-cell parameters are, a = 29.55, b = 42.18, c = 43.38 A, beta = 96.56 degrees, space group P21, with two molecules in the asymmetric unit, in contrast to all previous, side-by-side distamycin-DNA complexes which have only a single DNA strand, and one drug molecule in the asymmetric unit. The structure was solved by, the molecular-replacement method and refined to an R index of 21.0% using, 3467 reflections [>/= 2sigma(F)]. The minor grooves of the DNA molecules, bind two side-by-side antiparallel staggered distamycins spanning about, five base pairs and virtually covering the entire length of the DNA. The, octamer duplexes exhibit low-high alternations in the helical twist, sugar, puckering and the C-O3' and O3'-P torsion angles, similar to the earlier, side-by-side complexes containing inosine bases. The molecules are stacked, one over the other along the ac diagonal in an infinite pseudo-continuous, helical column with no lateral interactions.
About this Structure
378D is a Protein complex structure of sequences from [1] with and as ligands. Full crystallographic information is available from OCA.
Reference
Structure of the side-by-side binding of distamycin to d(GTATATAC)2., Mitra SN, Wahl MC, Sundaralingam M, Acta Crystallogr D Biol Crystallogr. 1999 Mar;55(Pt 3):602-9. PMID:10089456
Page seeded by OCA on Tue Jan 29 21:37:14 2008
