Transcriptome analysis during the production phase of menisporopsin A from Menisporopsis theobromae BCC 4162

Transcriptome analysis of M. theobromae identified an R-PKS gene, men1, and an NR-PKS gene, men2, that both exhibited highest expression levels during the menisporopsin A production phase. These were cloned into separate vectors for heterologous expression in Aspergillus oryzae NSAR1. Interestingly, coexpression of the two PKSs was found to be sufficient to catalyze the formation of ascotrichalactone A, a structural derivative of menisporopsin A. The unanticipated enzymatic activities could reside in the unusual thioesterase domain of the NR-PKS, which is similar to that of the NRPS catalyzing elongation and cyclization of trilactone in enterobactin biosynthesis and that of modular PKSs catalyzing macrodiolide formation in elaiophylin and conglobatin biosyntheses.