Genome mining reveals the unique function of UbiA-type prenyltransferase in Laetiporus sulphureus

Eight UbiA-type prenyltransferases were mined in Laetiporus sulphureus by bioinformatic analysis, and phylogenetic analysis showed that they have unique functions. Through heterologous expression in Aspergillus oryzae and addition of exogenous hydroquinone (HYQ, 2) substrate, it was found that LaPT3 could transfer isoprenyl groups on 2. Substrate specificity studies revealed that LaPT3 was substrate specific and could only transfer dimethylallyl diphosphate (DMAPP) using 2 as substrate to produce the product 2-(3-methylbut-2-en-1-yl) benzene-1,4-diol (1). The key active sites of LaPT3 were analyzed and two key amino acid sites near the conserved motifs were targeted for mutation, and the product yields were reduced to 60% and 29% respectively by mutating N100 to S and G208 to A. Molecular docking and site-directed mutagenesis results indicate that these two amino acid sites play a crucial role in the catalytic generation of 2 by LaPT3 to produce 1.