4bna
From Proteopedia
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REVERSIBLE BENDING AND HELIX GEOMETRY IN A B-DNA DODECAMER: CGCGAATTBRCGCG
Overview
A double-helical B-DNA dodecamer has been analyzed by single crystal x-ray, diffraction methods and refined independently in four variants: sequence, CGCGAATTCGCG at 20 degrees C and at 16 K, and CGCGAATTBrCGCG in 60%, methylpentanediol at 20 and at 7 degrees C. The first three forms show a, 14-19 degrees bend in overall helix axis, but the fourth is straight and, unbent. Detailed comparisons of the various forms have led to a better, understanding of helix geometry and bending. Structural principles can be, understood best if organized under four headings: 1) intrinsic geometry of, the sugar rings, 2) stacking and relative motion of base pairs, 3), geometry of the connecting phosphate backbone, and 4) mechanics of bending, in B-DNA. The observed bending is neither completely localized nor smooth, and continuous, but an intermediate compromise that can be termed, "annealed kinking."
About this Structure
4BNA is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Reversible bending and helix geometry in a B-DNA dodecamer: CGCGAATTBrCGCG., Fratini AV, Kopka ML, Drew HR, Dickerson RE, J Biol Chem. 1982 Dec 25;257(24):14686-707. PMID:7174662
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