Nucleic Acids Research, 1985, Vol. 13, No. 9 3343-3355
© 1985
Articles |
Influence of uracil defect on DNA structure: 1H NMR invastigation 500 MHz
Laboratoires de Chimie, Département de Recherche Fondamentale, Centre d'Etudes Nucléaires de Grenoble 85 X, F.38041 Grenoble Cédex, France +Service cit Biophysique, Département de Biologie, Centre d'Etudes Nucléaires de Saclay F.91191 Gif-sur-Yvette Cédex, France
*To whom correspondence should be addressed
Received February 25, 1985. Accepted March 22, 1985.
The local structure of two self complementary oligonucleotides d(GTAC-GTAC) and d(GTACGUAC) which differ only by the presence of uracil, not a normal component of DNA, have been investigated by 1H NMR at 500 MHz The two octamera exhibit the same thermodynamical constants (t1/2
H), their exchangeable protons broaden and disappear at the same temperature. The T-U substitution did not induce any significant changes on non exchangeable protons re sonances from 2-D COSY and 2-D NOESY experiments. So the two octamers exhibit the same global structure. The only variation was detected by 1D NOE measurements : the base orientations around the N glycosidic bonds (x angles) are different.