title: [Under what conditions does G.C Watson-Crick DNA base pair acquire all four configurations characteristic for A.T Watson-Crick DNA base pair?].
abstract: At the MP2/6-311++G(2df,pd)//B3LYP/6-311++G(d,p) level of theory it was established for the first time, that the Löwdin's G*.C* DNA base pair formed by the mutagenic tautomers can acquire, as the A-T Watson-Crick DNA base pair, four biologically important configurations, namely: Watson-Crick, reverse Watson-Crick, Hoogsteen and reverse Hoogsteen. This fact demonstrates rather unexpected role of the tautomerisation of the one of the Watson-Crick DNA base pairs, in particular, via double proton transfer: exactly the G.C-->G*.C* tautomerisation allows to overcome steric hindrances for the implementation of the above mentioned configurations. Geometric, electron-topological and energetic properties of the H-bonds that stabilise the studied pairs, as well as the energetic characteristics of the latters are presented.
authors: O O
authors: OO
authors: Brovarets'
mesh_terms: D000225:Adenine / Q000737:chemistry*; D020029:Base Pairing; D003596:Cytosine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009154:Mutation; D009690:Nucleic Acid Conformation; D011522:Protons; D013237:Stereoisomerism; D013816:Thermodynamics; D013941:Thymine / Q000737:chemistry*
chemical_list: D011522:Protons; D006147:Guanine; D003596:Cytosine; D004247:DNA; D000225:Adenine; D013941:Thymine