Cloning, functional characterization, and near-ultraviolet radiation-enhanced expression of a photolyase gene (PHR1) from the phytopathogenic fungus Bipolaris oryzae

Photolyase is a DNA repair enzyme that can absorb blue/ultraviolet A light as energy and split a pyrimidine dimer induced by ultraviolet radiation. We isolated and characterized PHR1, a gene encoding photolyase, from the phytopathogenic fungus Bipolaris oryzae. Sequence analysis showed that PHR1 encodes a putative protein that has 634 amino acids, a molecular mass of 72.6 kDa, and 51.3-55.5% sequence identity to other fungal photolyases. Complementation of the photoreactivation-deficient Escherichia coli mutant by PHR1 cDNA demonstrated that the PHR1 gene from B. oryzae encodes a functional photolyase. Real-time PCR analysis showed that the PHR1 transcripts were specifically enhanced by near-ultraviolet radiation (300-400 nm) and by sunlight.