The effect of chlorination of nucleotide bases on the conformational properties of thymidine monophosphate

Abstract

Recent studies on Escherichia coli bacteria cultivation, in which DNA thymine was replaced with 5-chlorouracil have refreshed the problem of understanding the changes to physical properties of DNA monomers resultant from chemical modifications. These studies have shown that the replacement did not affect the normal activities and division of the bacteria, but has significantly reduced its life span. In this paper a comparative analysis was carried out by the methods of computational experiment of a set of 687 possible conformers of natural monomeric DNA unit (2′-deoxyribonucleotide thymidine monophosphate) and 660 conformers of 5-chloro-2′-deoxyuridine monophosphate – a similar molecules in which the natural nitrogenous base thymine is substituted with 5-chlorouracil. Structures of stable conformers of the modified deoxyribonucleotide have been obtained and physical factors, which determine their variation from the conformers of the unmodified molecule have been analyzed. A comparative analysis of the elastic properties of conformers­ of investigated molecules and non-covalent interactions present in them was conducted. The results can be used for planning experiments on synthesis of artificial DNA suitable for incorporation into living organisms.

Keywords

• 5-chlorouracil
• conformational analysis
• deoxyribonucleotides
• DNA
• Escherichia coli
• nucleotide base