The synthetic dodecanucleotide d(CGCAAATTGGCG) has been analysed by single-crystal X-ray diffraction techniques and the structure refined to R = 0.16 and 2.25 A resolution, with the location of 94 solvent molecules. The sequence crystallizes as a full turn of a B-DNA helix with ten Watson-Crick base-pairs and two adenine-guanine mispairs. The analysis clearly shows that the mismatches are of the form A(anti).G(syn). Thermal denaturation studies indicate that the stability of the duplex is strongly pH dependent, with a maximum at pH 5.0, suggesting that the base-pair is stabilized by protonation. Three different arrangements have been observed for base-pairs between guanine and adenine and it is likely that A.G mismatch conformation is strongly influenced by dipole-dipole interactions with adjacent base-pairs.
Crystal structure and stability of a DNA duplex containing A(anti).G(syn) base-pairs.,Brown T, Leonard GA, Booth ED, Chambers J J Mol Biol. 1989 May 20;207(2):455-7. PMID:2754734[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Brown T, Leonard GA, Booth ED, Chambers J. Crystal structure and stability of a DNA duplex containing A(anti).G(syn) base-pairs. J Mol Biol. 1989 May 20;207(2):455-7. PMID:2754734
