Ultraviolet-B (UV-B, 280–320 nm) radiation may have severe negative effects on plants including damage to their genetic information. UV protection and DNA repair mechanisms have evolved to either avoid or repair such damage. Since autotrophic plants are dependent on sunlight for their energy supply, an increase in the amount of UV-B reaching the earth’s surface may affect the integrity of their genetic information if DNA damage is not repaired efficiently and rapidly. Here we show that overexpression of cyclobutane pyrimidine dimer (CPD) Photolyase (EC 4.1.99.3) in Arabidopsis thaliana (L.), which catalyses the reversion of the major UV-B photoproduct in DNA (CPDs), strongly enhances the repair of CPDs and results in a moderate increase of biomass production under elevated UV-B.
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 into the binding site for the antenna Chromophore paves the way for wavelength-tuning of the activity spectra of DNA photolyases by using flavins.
Kaiser, Gebhard Alexander (1021155586): Verbesserte in vitro und in planta DNA-Reparatur durch CPD-Photolyasen.. : Philipps-Universität Marburg 2012-05-18. DOI: https://doi.org/10.17192/z2012.0125.
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