Nonribosomal peptide synthetase; part of the gene cluster that mediates the biosynthesis of pyrrolopyrazines, secondary metabolites showing insecticidal activity (PubMed:30452111). The single multifunctional NRPS ppzA is responsible for the biosynthesis of peramine (PubMed:30452111). The condensation domain of ppzA is proposed to catalyze formation of a peptide bond between 1-pyrroline-5-carboxylate and arginine (By similarity). The methylation domain of ppzA would catalyze the N-methylation of the alpha-amino group of arginine (By similarity). The reductase domain is proposed to be responsible for reduction of the thioester and the cyclization to form an iminium ion resulting in release from the peptide synthetase (By similarity). Deprotonation of this intermediate and oxidation of the pyrroline ring would give rise to peramine (By similarity). This final oxidation to give the pyrrole functionality may be spontaneous (By similarity). In Epichloe species that produce only peramine, the peramine synthetase gene is not localized in a gene cluster, in contrast to Metarhizium rileyi that contains additionnal pyrrolopyrazine biosynthesis genes (Probable). The 2-oxoglutarate-Fe(II) type oxidoreductases ppzC and ppzD could be candidates for conversion of proline into an oxidized derivative to be used by the ppzA A1-domain as substrate (Probable). The other ppz genes encode proteins predicted to derivatize peramine into more complex pyrrolopyrazine metabolites (Probable). 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. 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, methyltransferase domains (responsible for amino acid methylation) are present within the NRP synthetase. PpzA has the following architecture: A-T-C-A-Met-T-TE. Belongs to the NRP synthetase family.