Known product releasing mechanisms of fungal HRPKSs. (A) Product release is catalyzed by a separate TE or acyltransferase through hydrolysis or transesterification; (B) C domain serves as the releasing domain in the biosynthesis of fungal aminoacylated polyketide products. Domain abbreviations: KS, ketosynthase; MAT, malonyl-CoA:ACP transacylase; DH, dehydratase; MT, methyltransferase; ER, enoyl reductase; KR, ketoreductase; ACP, acyl carrier protein; C, condensation; A, adenylation; T, thiolation; R, reductase.