Open AccessDNA variability in five crystal structures of d(CGCAATTGCG)
Author(s) -
Valls Núria,
Wright Glenford,
Steiner Roberto A.,
Murshudov Garib N.,
Subirana Juan A.
Publication year - 2004
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444904002896
Subject(s) - random hexamer , crystallography , resolution (logic) , guanine , crystal structure , crystal (programming language) , sequence (biology) , chemistry , dna , nucleotide , biochemistry , artificial intelligence , computer science , programming language , gene
The deoxyoligonucleotide d(CGCAATTGCG) has previously been crystallized in four different space groups. The crystals diffract to moderate resolution (2.3–2.9 Å). Here, a fifth crystal form that diffracts to higher resolution (1.6 Å) is presented which was obtained thanks to the use of Co 2+ 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–Co 2+ –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.