Crystal structure of a four-stranded intercalated DNA: d(C4).
The crystal structure of d(C4) solved at 2.3-A resolution reveals a four-stranded molecule composed of two interdigitated or intercalated duplexes. The duplexes are held together by hemiprotonated cytosine-cytosine base pairs and are parallel stranded, but the two duplexes point in opposite directions. The molecule has a slow right-handed twist of 12.4 degrees between covalently linked cytosine base pairs, and the base stacking distance is 3.1 A. This is in general agreement with the NMR studies. A biological role for DNA in this conformation is suggested.
Chen
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Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Cai
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L
Zhang
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Rich
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D003196:Computer Graphics; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D009690:Nucleic Acid Conformation
D004247:DNA