The role of the bacterial mismatch repair system in SOS-induced mutagenesis: A theoretical background

• A mathematical model of the bacterial DNA mismatch repair system is developed.
• Five key pathways of the Escherichia coli mismatch repair are simulated adequately.
• The relationships between SOS and MMR systems are described quantitatively.
• A possible mechanistic explanation of MMR role in UV-mutagenesis is shown.

A theoretical study is performed of the possible role of the methyl-directed mismatch repair system in the ultraviolet-induced mutagenesis of Escherichia coli bacterial cells. For this purpose, mathematical models of the SOS network, translesion synthesis and mismatch repair are developed. Within the proposed models, the key pathways of these repair systems were simulated on the basis of modern experimental data related to their mechanisms. Our model approach shows a possible mechanistic explanation of the hypothesis that the bacterial mismatch repair system is responsible for attenuation of mutation frequency during ultraviolet-induced SOS response via removal of the nucleotides misincorporated by DNA polymerase V (the UmuD'2C complex).