Nonribosomal peptide synthetase; part of the gene cluster that mediates the biosynthesis of astellolides, drimane-type sesquiterpene esters that show antimicrobial, anti-inflammatory, and anti-tumor activities (PubMed:27628599). The first step in astellolide biosynthesis is performed by the sesquiterpene cyclase astC that catalyzes the formation of drimanyl pyrophosphate from farnesyl pyrophosphate (PubMed:27628599). Drimanyl pyrophosphate is then dephosphorylated by the sesquiterpene phosphatase astI to produce drimanyl monophosphate which is further dephosphorylated to drim-8-ene-11-ol by atsK (PubMed:27628599). Drim-8-ene-11-ol is converted to confertifolin, probably by the cytochrome P450 monooxygenase astD and/or the dehydrogenase astE (PubMed:27628599). The cytochrome P450 monooxygenases astB, astF and astJ then hydroxylate confertifolin at C6, C14, or C15 to form trihydroxy confertifolin (PubMed:27628599). The nonribosomal peptide synthetase astA catalyzes ester bond formation between trihydroxy contifolin and benzoic acid (BA) or 4-hydroxy benzoic acid (4HBA), leading to the formation of dideacetyl astellolides A and B, respectively (PubMed:27628599). Finally, the O-acetyltransferase astG converts dideacetyl astellolides A and B into deacetyl astellolides A and B (PubMed:27628599). Secondary metabolite biosynthesis; terpenoid biosynthesis. Expression is regulated by the secondary metabolite regulator cclA. NRP synthetases are composed of discrete domains (adenylation (A), thiolation (T) or peptidyl carrier protein (PCP) and condensation (C) domains) which when grouped together are referred to as a single module. Each module is responsible for the recognition (via the A domain) and incorporation of a single amino acid into the growing peptide product. Thus, an NRP synthetase is generally composed of one or more modules and can terminate in a thioesterase domain (TE) that releases the newly synthesized peptide from the enzyme. Occasionally, epimerase (E) domains (responsible for L- to D- amino acid conversion) are present within the NRP synthetase. AsrA has the following single module architecture: A-T-C. Impairs the production of deacetyl astellolides A and B and leads to the accumulation of trihydroxy confertifolin. Belongs to the NRP synthetase family.