Natural and Non‐natural Antenna Chromophores in the DNA Photolyase from Thermus Thermophilus

Abstract

X‐ray crystallographic and functional analysis of the class I DNA photolyase from Thermus thermophilus revealed the binding of flavin mononucleotide (FMN) as an antenna chromophore. The binding mode of FMN closely coincides with the binding of a deazaflavin‐like chromophore in the related class I DNA photolyase from Anacystis nidulans. Compared to the R46E mutant, which lacks a conserved arginine in the binding site for the antenna chromophore, the FMN‐comprising holophotolyase exhibits an eightfold higher activity at 450 nm. The facile incorporation of the flavin cofactors 8‐hydroxy‐deazariboflavin and 8‐iodo‐8‐demethyl‐riboflavin into the binding site for the antenna chromophore paves the way for wavelength‐tuning of the activity spectra of DNA photolyases by using synthetic flavins.