1s23
From Proteopedia
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| , resolution 1.60Å | |||||||
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure Analysis of the B-DNA Decamer CGCAATTGCG
Overview
The deoxyoligonucleotide d(CGCAATTGCG) has previously been crystallized in four different space groups. The crystals diffract to moderate resolution (2.3-2.9 A). Here, a fifth crystal form that diffracts to higher resolution (1.6 A) is presented which was obtained thanks to the use of Co2+ and cryogenic temperatures. The availability of five different crystal structures allows a thorough analysis of the conformational variability of this DNA sequence. It is concluded that the central hexamer sequence CAATTG has a practically constant conformation under all conditions, whilst the terminal base pairs at both ends vary considerably as a result of differing interactions in the crystals. The new crystal structure presented here is stabilized by guanine-Co2+-guanine interactions and the formation of C1+ -G8.C3 triplexes between neighbouring duplexes. As a result of the higher resolution of the crystal structure, a more regular structure was obtained and a clear definition of the spine of hydration was observed which was not visible in the four previous structures.
About this Structure
1S23 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
DNA variability in five crystal structures of d(CGCAATTGCG)., Valls N, Wright G, Steiner RA, Murshudov GN, Subirana JA, Acta Crystallogr D Biol Crystallogr. 2004 Apr;60(Pt 4):680-5. Epub 2004, Mar 23. PMID:15039556
Page seeded by OCA on Thu Mar 20 13:59:25 2008
