Bifunctional photolyases are widespread in different bacteria genus: a comprehensive phylogenetic study.

FERNÁNDEZ, BELÉN; LATORRE, LUCAS; CASSIA, R.

Santa Fe

Congreso; Edición virtual. RAFV 2021; 2021

SAFV

Photolyases are flavoenzymes from the cryptochrome/ photolyase family. They repair DNA damage induced by ultraviolet- B (UV-B) radiation in a blue and UV-A light driven mechanism. Photolyases repair cyclobutane pyrimidine dimers (CPD), the major UV-B damage (75%), and pyrimidine-pyrimidone (6?4) photoproducts (6?4PP). The first bifunctional photolyase, which is able to repair both types of DNA damage, it was recently reported in the antartic bacteria Sphingomonas sp SV9. We performed BlastP analysis to analyze if this enzyme would be present in other bacteria. All the retrieved sequences matched the criteria of E- values lower than 0.001 (being lower to 1x10-63) and percentage identities higher than 30%.() Subsequently, both partial sequences and those with percentage identities below 85% were identified and discarded using CD-HIT software. Then, we performed multiple sequence alignment (MSA), alignment curation and phylogenetic tree inference. This analysis revealed that over a total of 149 sequences, 55 were predicted as bifunctional photolyases. MSA analysis showed conservation of tryptophan´s important for electron transfer required for lesion repair in the predicted bifunctional photolyases. It was also observed that aminoacids involved in FAD and DNA lesion binding were conserved . These enzymes are widespread in several genus of bacteria, including cyanobacteria, proteobacteria, plantomycete, bacteroidete and acidobacteria. Finally, phylogenetic analysis including 6-4PP, CPD and bifunctional photolyases and other members from the cryptochrome/ photolyase family demonstrated that bifunctional enzymes may represent a transition from 6-4PP to CPD specific photolyases.