375d
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A NOVEL END-TO-END BINDING OF TWO NETROPSINS TO THE DNA DECAMER D(CCCCCIIIII)2
OverviewOverview
Netropsin is bound to the DNA decamer d(CCCCCIIIII)2, the C-4 bromo, derivative d(CCCBr5CCIIIII)2and the C-2 bromo derivative, d(CBr5CCCCIIIII)2in a novel 2:1 mode. Complexes of the native decamer and, the C-4 bromo derivative are isomorphous, space group P1, unit cell, dimensions a = 32.56 A (32.66), b = 32.59 A (32.77), c = 37.64 A (37.71), alpha = 86.30 degrees (86.01 degrees), beta = 84.50 degrees (84.37, degrees), gamma = 68.58 degrees (68.90 degrees) with two independent, molecules (A and B) in the asymmetric unit (values in parentheses are for, the derivative). The C-2 bromo derivative is hexagonal P61, unit cell, dimensions a = b = 32.13 A, c = 143.92, gamma = 120 degrees with one, molecule in the asymmetric unit. The structures were solved by the, molecular replacement method. The novelty of the structures is that there, are two netropsins bound end-to-end in the minor groove of each B-DNA, decamer which has nearly a complete turn. The netropsins are held by, hydrogen bonding interactions to the base atoms and by sandwiching van der, Waal's interactions from the sugar-phosphate backbones of the double helix, similar to every other drug.DNA complex. Each netropsin molecule spans, approximately 5 bp. The netropsins refined with their guanidinium heads, facing each other at the center, although an orientational disorder for, the netropsins cannot be excluded. The amidinium ends stretch out toward, the junctions and bind to the adjacent duplexes in the columns of stacked, symmetry-related complexes. Both cationic ends of netropsin are bridged by, water molecules in one of the independent molecules (molecule A) of the, triclinic structures and also the hexagonal structure to form, pseudo-continuous drug.decamer helices.
About this StructureAbout this Structure
375D is a Protein complex structure of sequences from [1] with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
A novel end-to-end binding of two netropsins to the DNA decamers d(CCCCCIIIII)2, d(CCCBr5CCIIIII)2and d(CBr5CCCCIIIII)2., Chen X, Mitra SN, Rao ST, Sekar K, Sundaralingam M, Nucleic Acids Res. 1998 Dec 1;26(23):5464-71. PMID:9826773
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