Nonribosomal peptide synthase; part of the gene cluster that mediates the biosynthesis of aculenes, a unique type of norsesquiterpenes that contain a nordaucane skeleton linked to an L-proline moiety and are of mixed biosynthetic origin (PubMed:31618514). The pathway begins with the synthesis of dauca-4,7-diene by the terpene cyclase aneC using farnesyl pyrophosphate (FPP) as substrate (PubMed:31618514). The cytochrome P450 monooxygenase aneF then performs the initial oxidation at C-12 of dauca-4,7-diene to yield asperaculane D (PubMed:31618514). Asperaculane D is substrate of the cytochrome P450 monooxygenase aneD for C-10 hydroxylation to yield asperaculane E (PubMed:31618514). The cytochrome P450 monooxygenase aneG then converts asperaculane E into aculene D via C-2 oxidation (PubMed:31618514). The monomodular nonribosomal peptide synthase aneB adenylates L-proline and the thiohydrolase aneE transfers this activated L-proline derivative to aculenes D and C to produce respectively aculenes B and A (PubMed:31618514). The dioxygenase aneA converts aculene D into aculene C, and aculene B into aculene A by introducing the 5,6-alkene moiety (PubMed:31618514). Asperculanes A, B, C and F, as well as 14-prolyl asperculane C, might be shunt products of the pathway (PubMed:31618514). ATP + holo-[peptidyl-carrier protein] + L-proline = AMP + diphosphate + L-prolyl-[peptidyl-carrier protein] Secondary metabolite biosynthesis. 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 (Probable). AneB has a monomodular A-T-C architecture (Probable). Abolishes the production of aculenes A and B and accumulates aculenes C and D. Belongs to the NRP synthetase family.