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DNA base stacking: The stacked uracil/uracil and thymine/thymine minima
Author(s) -
Hunter Ruairidh S.,
van Mourik Tanja
Publication year - 2012
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.23052
Subject(s) - thymine , uracil , dimer , chemistry , stacking , polarizable continuum model , monomer , crystallography , molecule , basis set , potential energy surface , computational chemistry , molecular physics , solvation , density functional theory , dna , organic chemistry , biochemistry , polymer
The potential energy surfaces of stacked uracil dimer (U/U) and stacked thymine dimer (T/T) have been explored at the counterpoise (CP)‐corrected M06‐2X/6‐31+G(d) level of theory, in the gas phase and in solution (with water and, for U/U, 1,4‐dioxane as the solvents) modeled by a continuum solvent using the polarizable continuum model. Potential energy scans were created by rotation of one monomer around its center‐of‐mass, whereas the other monomer remained still. Both face‐to‐back (one molecule exactly on top of the other) and face‐to‐face (one base molecule flipped by 180°) structures were considered. Five or six (dependent on whether CP correction is included or not) stacked uracil dimer minima and six stacked thymine dimer minima were located. A number of transition states on the U/U and T/T potential energy surfaces were likewise identified. The general effect of the continuum solvent is a flattening of the potential energy surface. Comparison of the gas‐phase M06‐2X/6‐31+G(d) U/U interaction energies with estimated CCSD(T)/complete basis set values (where available) show the excellent performance of this functional for stacking energies. © 2012 Wiley Periodicals, Inc.