The deoxyoligonucleotide d(BrU-G-C-G-C-G) was crystallised at pH 8.2 and its structure analysed by X-ray diffraction. The unit cell, of dimensions a = 17.94, b = 30.85, c = 49.94A contains four DNA duplexes in space group P2(1)2(1)2(1). The duplexes are in the Z conformation, with four Watson-Crick G.C base pairs and two BrU.G base pairs. The structure was refined to an R factor of 0.16 at a resolution of 2.2A with 64 solvent molecules located. The BrU.G base pair mismatch is of the wobble type, with both bases in the major tautomer form and hydrogen bonds linking 0-2 of BrU with N-1 of G and N3 of BrU with 0-6 of G. There is no indication of the presence of ionised base pairs, in spite of the high pH of crystallisation. The results are discussed in terms of the mutagenic properties of 5- bromouracil.
Structural characterisation of the bromouracil.guanine base pair mismatch in a Z-DNA fragment.,Brown T, Kneale G, Hunter WN, Kennard O Nucleic Acids Res. 1986 Feb 25;14(4):1801-9. PMID:3951996[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Brown T, Kneale G, Hunter WN, Kennard O. Structural characterisation of the bromouracil.guanine base pair mismatch in a Z-DNA fragment. Nucleic Acids Res. 1986 Feb 25;14(4):1801-9. PMID:3951996
