Functional expression of 8-hydroxy-5-deazaflavin-dependent DNA photolyase from Anacystis nidulans in Streptomyces coelicolor

The gene encoding Anacystis nidulans 5-deazaflavin-dependent photolyase (phr) was inserted into the Streptomyces vector pIJ385 to form a transcriptional fusion with the neomycin resistance (aph) gene. The resulting plasmid, pANPL, was introduced into Streptomyces coelicolor, a host which exhibits no detectable photolyase activity and provides 5-deazaflavins. Transformants expressed functional photolyase and could be cultured at much higher cell densities than A. nidulans. A two-step affinity protocol was used to purify photolyase to homogeneity. High-pressure liquid chromatographic analysis established the presence of 5-deazaflavin cofactors in the enzyme, showing that this expression system allows heterologous production of 5-deazaflavin-class photolyases.