The efficiency of photolyase and indole complexes to repair DNA containing dimers of pyrimidine: a theoretical analysis of the electron transfer reactions

We analyze the effects of competing reactions to the efficiency of enzymatic splitting of pyrimidine dimers formed in DNA by the incidence of ultraviolet radiation. This is accomplished with the aid of a formula that expresses the efficiency of the repair in terms of parameters that regulate the reaction rates for primary and for back long-range electron transfers taking place in the process. Comparison of experimental data with estimations on account of this formula supports early conjectures in the literature that attribute the relative high performance of the enzymatic complexes of photolyase to its ability to suppress the back reaction.