Polyprenyl transferase; part of the gene cluster A that mediates the biosynthesis of the fungal meroterpenoid acetoxydehydroaustin (PubMed:29076725). The first step of the pathway is the synthesis of 3,5-dimethylorsellinic acid by the polyketide synthase ausA (By similarity). 3,5-dimethylorsellinic acid is then prenylated by the polyprenyl transferase ausN (By similarity). Further epoxidation by the FAD-dependent monooxygenase ausM and cyclization by the probable terpene cyclase ausL lead to the formation of protoaustinoid A (By similarity). Protoaustinoid A is then oxidized to spiro-lactone preaustinoid A3 by the combined action of the FAD-binding monooxygenases ausB and ausC, and the dioxygenase ausE (By similarity). Acid-catalyzed keto-rearrangement and ring contraction of the tetraketide portion of preaustinoid A3 by ausJ lead to the formation of preaustinoid A4 (By similarity). The aldo-keto reductase ausK, with the help of ausH, is involved in the next step by transforming preaustinoid A4 into isoaustinone which is in turn hydroxylated by the P450 monooxygenase ausI to form austinolide (By similarity). The cytochrome P450 monooxygenase ausG then modifies austinolide to austinol (By similarity). Austinol is further acetylated to austin by the O-acetyltransferase ausP, which spontaneously changes to dehydroaustin (PubMed:29076725). The cytochrome P450 monooxygenase then converts dehydroaustin is into 7-dehydrodehydroaustin (PubMed:29076725). The hydroxylation catalyzed by ausR permits the second O-acetyltransferase ausQ to add an additional acetyl group to the molecule, leading to the formation of acetoxydehydroaustin (PubMed:29076725). Due to genetic rearrangements of the clusters and the subsequent loss of some enzymes, the end product of the Penicillium brasilianum austinoid biosynthesis clusters is acetoxydehydroaustin (PubMed:29076725). (2E,6E)-farnesyl diphosphate + 3,5-dimethylorsellinate = (3R)-3-farnesyl-6-hydroxy-2,3,5-trimethyl-4-oxocyclohexa-1,5-diene-1-carboxylate + diphosphate + H(+) Secondary metabolite biosynthesis; terpenoid biosynthesis. In A.calidoustus, the austinoid gene cluster lies on a contiguous DNA region, while clusters from E.nidulans and P.brasilianum are split in their respective genomes. Genetic rearrangements provoked variability among the clusters and E.nidulans produces the least number of austionoid derivatives with the end products austinol and dehydroaustinol, while P.brasilianum can produce until acetoxydehydroaustin, and A.calidoustus produces the highest number of identified derivatives. Belongs to the UbiA prenyltransferase family.