237d
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CRYSTAL STRUCTURE OF A DNA DECAMER SHOWING A NOVEL PSEUDO FOUR-WAY HELIX-HELIX JUNCTION
OverviewOverview
The crystal structure of the decanucleotide d(CGCAATTGCG)2 has been solved by a combination of molecular replacement and heavy-atom procedures and has been refined to an R factor of 20.2% at 2.7 A. It is not a fully base-paired duplex but has a central core of eight Watson-Crick base pairs flanked by unpaired terminal guanosines and cytosines. These participate in hydrogen-bonding arrangements with adjacent decamer duplexes in the crystal lattice. The unpaired guanosines are bound in the G+C regions of duplex minor grooves. The cytosines have relatively high mobility, even though they are constrained to be in one region where they are involved in base-paired triplets with G.C base pairs. The 5'-AATT sequence in the duplex region has a narrow minor groove, providing further confirmation of the sequence-dependent nature of groove width.
About this StructureAbout this Structure
237D is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of a DNA decamer showing a novel pseudo four-way helix-helix junction., Spink N, Nunn CM, Vojtechovsky J, Berman HM, Neidle S, Proc Natl Acad Sci U S A. 1995 Nov 7;92(23):10767-71. PMID:7479880
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