Molecular dynamics simulation of clustered DNA damage sites containing 8-oxoguanine and abasic site

Fujimoto, Hirofumi*; Pinak, M.; Nemoto, Toshiyuki*; O'Neill, P.*; Kume, Etsuo ; Saito, Kimiaki  ; Maekawa, Hideaki*

Clustered DNA damage sites induced by ionizing radiation have been suggested to have serious consequences to organisms. In this study, approaches based on molecular dynamics (MD) simulation have been applied to examine conformational changes and energetic properties of DNA molecules containing clustered damage sites consisting of 2 lesioned sites, 8-oxoG and AP site. After 1 nanosecond of MD simulation, one of the 6 DNA molecules containing a clustered damage site develop specific characteristic features: sharp bending at the lesioned site and weakening or complete loss of electrostatic interaction energy between 8-oxoG and bases locating on the complementary strand. From these results it is suggested that these changes would make it difficult for the repair enzyme to bind to the lesions within the clustered damage site and thereby result in a reduction of its repair capacity.