We have examined the reactivity of B DNA with two chemical probes of DNA structure, potassium permanganate (KMnO4; thymine specific) and diethyl pyrocarbonate (DEPC; purine specific, A greater than G). The DNA probed is from the beta-lactamase promoter region of the vector pBR322, and from the 3' noncoding region of a chicken embryonic myosin heavy chain gene. The chemical probes display variab...

We have performed quantum-chemical ab initio in various basis sets at the Hartree-Fock andB3LYP levels for Adenine and Thymine with the program GAUSSIAN98. The Dipole,Quadrupole, Octapole and Hexadecapole moments and primitive in nine basis sets for thesemolecules are presented. The most stabilized forms of these molecules are observed in 6-311++G** basis set. We have evaluated coefficient hybr...

The relative stability of the normal and tautomeric forms of adenine and thymine has been formerly analysed with semi-empirical and abinitio methods [1—2]. In the same way we have now calculated the charge distribution of several excited states in order to determine the intramolecular charge transfer involved in the tautomerization process. Moreover, we have obtained the direction of the polari...

The ionization potentials and electron affinities of thymine, cytosine, adenine, guanine, and uracil were determined at density functional level using different exchange-correlation functionals and basis sets. Results showed that the computed ionization potentials are very close to the experimental counterparts. The sign of adiabatic electron affinities of adenine, thymine, and uracil is unaffe...

The hydration of biomolecules is vitally important in molecular biology, so in this paper thesolvation energy and radial distribution function of DNA bases have been calculated by theMonte Carlo simulation.The geometries of isolated Adenine, Guanine, Cytosine, and Thyminehave been optimized using 6-31+G(d,p) basis function sets. These geometries then will be used inthe Monte Carlo calculation o...

The role of thymine dimerization for previously reported U.V. induced conformational changes has been proved using acetophenone as sensitizer for the specific thymine dimerization upon irradiation at 313 nm. CD results demonstrate that formation of pyrimidine dimers cause typical conformational changes of the DNA B helix as observed on irradiation at 254 nm. Thus the primary role of adenine pho...

the hydration of biomolecules is vitally important in molecular biology, so in this paper thesolvation energy and radial distribution function of dna bases have been calculated by themonte carlo simulation.the geometries of isolated adenine, guanine, cytosine, and thyminehave been optimized using 6-31+g(d,p) basis function sets. these geometries then will be used inthe monte carlo calculation o...

The results of geometry optimisation of possible Watson-Crick-like pairs of 2,6-diamino-4-oxy-5-formamidopyrimidine (fapy-adenine) or 4,6-diamino-5-formamidopyrimidine (fapy-guanine) were presented. In the absence of the external field the fapy-adenine is able to form pairs with all four canonical nucleic acid bases. However, pairs with guanine, cytosine and thymine the most stable are. Thus, t...

Mig.MthI from Methanobacterium thermoautotrophicum and MutY of Escherichia coli are both DNA mismatch glycosylases of the 'helix-hairpin-helix' (HhH) superfamily of DNA repair glycosylases; the former excises thymine from T/G, the latter adenine from A/G mismatches. The structure of MutY, in complex with its low molecular weight product, adenine, has previously been determined by X-ray crystall...