“False” Thymine-1H-Enol Guanine Base Pair. Low Misinsertion Rate by DNA Polymerase Explained by Computational Chemistry Consideration

---

E. Seclaman^1,2, L. Kurunczi^1,2, and Z. Simon^2*

¹University of Medicine and Pharmacy “Victor Babes” Timisoara, Eftimie Murgu 2, 300041 Timisoara, Romania; fax: 40256-220-479; E-mail: eddie@acad-icht.tm.edu.ro; dick@acad-icht.tm.edu.ro

²Romanian Academy, Institute of Chemistry Timisoara, Mihai Viteazul 24, 300223 Timisoara, Romania; fax: 40256-491-824; E-mail: zsimon@acad-icht.tm.edu.ro

^* To whom correspondence should be addressed.

Received September 18, 2006; Revision received November 2, 2006

---

Formation of correct TA and GC and “false” thymine-1H-enol guanine (TGenol) base pairs is here considered to control nucleotide insertion into DNA via low substrate concentration Michaelis-Menten controlled kinetics. Contributions of base pairing to formation of Gibbs free energies in water solution, DeltaDeltaG, are calculated for the correct and false base pairs with the semi-empiric MNDO/PM3 method for base pairing energies in vacuum and the BEM method for hydration effects. The results for DeltaDeltaG indicate equal insertion rates for correct base pairing and a 10^-3-10^-4 error probability for false insertion controlled by the TGenol false pair.

---

KEY WORDS: point mutation rates, misinsertion rates, enzymatic Michaelis-Menten kinetics, molecular energy in aqueous solution calculation, PM3

DOI: 10.1134/S000629790703011X

---