Nucleic Acids Research, 1990, Vol. 18, No. 14 4075
© 1990
CHEMISTRY |
An NMR structural study of deaminated base pairs in DNA
Service de Biochimie, Bât 142, Département de Biologie, Centre d'Etudes Nucléaires de Saclay F-91191 Gif-sur-Yvette Cedex, France 1Division of Pediatrics, City of Hope National Medical Center Duarte, CA 91010, USA
*To whom correspondence should be addressed
Received May 21, 1990. Accepted June 22, 1990.
The structurally aberrant base pairs TG, UG and Tl may occur in DNA as a consequence of deamination of 5-methylcytosine, cytosine and adenine respectively. Results of NMR spectroscopic studies are reported here for these deaminated base pairs in a model seven base pair long oligonucleotide duplex. We find that in all three cases, the DNA helix is a normal B form and both mispaired bases are intrahelical and hydrogen bonded with one another in a wobble geometry. Similarly, in all three cases, all sugars are found to be normal C2' endo in conformation. Symmetric structural perturbations are observed in the helix twist on the 3' side of the mispaired pyrimidine and on the 5' side of the mispaired purine. In all three cases, the amino group of the G residue on the 3' side of the mispaired pyrimidine shows hindered rotation. Although less thermodynamically stable than helices containing only Watson-Crick base pairs, these helices melt normally from the ends and not from the mispair outwards.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
P. Liu, A. Burdzy, and L. C. Sowers DNA ligases ensure fidelity by interrogating minor groove contacts Nucleic Acids Res., August 24, 2004; 32(15): 4503 - 4511. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Rusmintratip and L. C. Sowers An unexpectedly high excision capacity for mispaired 5-hydroxymethyluracil in human cell extracts PNAS, December 19, 2000; 97(26): 14183 - 14187. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Saparbaev, J.-C. Mani, and J. Laval Interactions of the human, rat, Saccharomyces cerevisiae and Escherichia coli 3-methyladenine-DNA glycosylases with DNA containing dIMP residues Nucleic Acids Res., March 15, 2000; 28(6): 1332 - 1339. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. S. Kingma and N. Osheroff Spontaneous DNA Damage Stimulates Topoisomerase II-mediated DNA Cleavage J. Biol. Chem., March 14, 1997; 272(11): 7488 - 7493. [Abstract] [Full Text] [PDF] |
||||


