4BNA

REVERSIBLE BENDING AND HELIX GEOMETRY IN A B-DNA DODECAMER: CGCGAATTBRCGCG

Summary for 4BNA

• Entry DOI: 10.2210/pdb4bna/pdb
• Descriptor: DNA (5'-D(*CP*GP*CP*GP*AP*AP*TP*TP*(CBR)P*GP*CP*G)-3') (2 entities in total)
• Functional Keywords: b-dna, double helix, modified, dna
• Total number of polymer chains: 2
• Total formula weight: 7484.58

Authors

Kopka, M.L.,Fratini, A.V.,Dickerson, R.E. (deposition date: 1982-02-16, release date: 1982-04-15, Last modification date: 2024-02-28)

Primary citation

Fratini, A.V.,Kopka, M.L.,Drew, H.R.,Dickerson, R.E.
Reversible bending and helix geometry in a B-DNA dodecamer: CGCGAATTBrCGCG.
J.Biol.Chem., 257:14686-14707, 1982

PubMed Abstract: 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."

PubMed: 7174662

Experimental method

X-RAY DIFFRACTION (2.3 Å)