Nonribosomal peptide synthetase; part of the gene cluster that mediates the biosynthesis of fumitremorgins, indole alkaloids that carry not only intriguing chemical structures, but also interesting biological and pharmacological activities (PubMed:23109474). The biosynthesis of fumitremorgin-type alkaloids begins by condensation of the two amino acids L-tryptophan and L-proline to brevianamide F, catalyzed by the non-ribosomal peptide synthetase ftmPS/ftmA (By similarity). Brevianamide F is then prenylated by the prenyltransferase ftmPT1/ftmB in the presence of dimethylallyl diphosphate, resulting in the formation of tryprostatin B (By similarity). The three cytochrome P450 monooxygenases, ftmP450-1/ftmC, ftmP450-2/ftmE and ftmP450-3/FtmG, are responsible for the conversion of tryprostatin B to 6-hydroxytryprostatin B, tryprostatin A to fumitremorgin C and fumitremorgin C to 12,13-dihydroxyfumitremorgin C, respectively (By similarity). The putative methyltransferase ftmMT/ftmD is expected for the conversion of 6-hydroxytryprostatin B to tryprostatin A (By similarity). FtmPT2/FtmH catalyzes the prenylation of 12,13-dihydroxyfumitre-morgin C in the presence of dimethylallyl diphosphate, resulting in the formation of fumitremorgin B (By similarity). Fumitremorgin B is further converted to verruculogen by ftmOx1/ftmF via the insertion of an endoperoxide bond between the two prenyl moieties (By similarity). Finally, verruculogen is further converted to fumitremorgin A by the verruculogen prenyltransferase ftmPT3 (PubMed:23109474). 2 ATP + L-proline + L-tryptophan = 2 AMP + brevianamide F + 2 diphosphate + 2 H(+) Mycotoxin 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. 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. NRPS13 has the following architecture: A-T-C-A-T-C. Belongs to the NRP synthetase family.