Theoretical Ab initio study of the effects of methylation on the nature of hydrogen bonding in A:T base pair.
We report the results of a theoretical ab initio study of methylation in Watson-Crick A:T base pairs. Equilibrium geometries were obtained without symmetry restrictions by the gradient procedure at DFT level of theory with the standard 6-31G(d) basis set. Each local minima was verified by energy second derivative calculations. Single-point calculations for the DFT geometries have been performed at the MP2/6-31G(d,p), MP2/6-31++G(d,p), and MP2/6-311++G(2d,2p) levels of theory. The geometrical parameters, relative stabilities and counterpoise corrected interaction energies are reported. In addition, using a variation-perturbation energy decomposition scheme, we have found the important contributions to the total interaction energy.
Flood
Aviane
A
Computational Center for Molecular Structure and Interactions, Jackson State University, Jackson, MS 39217, USA.
Hubbard
Curinetha
C
Forde
Gareth
G
Hill
Glake
G
Gorb
Leonid
L
Leszczynski
Jerzy
J
D000225:Adenine / Q000737:chemistry*; D020029:Base Pairing; D019175:DNA Methylation; D006801:Humans; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008962:Models, Theoretical; D013941:Thymine / Q000737:chemistry*
D000225:Adenine; D013941:Thymine