The gene PatG involved in the biosynthesis pathway of patulin, a food-borne mycotoxin, encodes a 6-methylsalicylic acid decarboxylase

The coding sequence was used to enable heterologous expression of functional enzymes in Saccharomyces cerevisiae. The presence of decarboxylase was confirmed by Western blot. The bioconversion assays showed that PATG catalyzed the decarboxylation of 6-methylsalicylic acid into m-cresol. These results confirm for the first time that 6-methylsalicylic acid is the substrate for PATG, the 6-methylsalicylic acid decarboxylase. With this study, the four genes involved in the four first steps of patulin biosynthesis pathway (acetate → gentisyl alcohol) are now identified.