Nonribosomal peptide synthetase that synthesizes enniatin by coupling three D-hydroxycarboxylic acids and three L-amino acids via amide and ester bonds in an alternating fashion (By similarity). Whereas ESYN1 can accept different amino acids as precursors (L -valine, L-isoleucine or L-leucine), only one species of D-hydroxycarboxylic acid can be found in natural enniatin isolates (D-hydroxyisovaleric acid, D-Hiv) (By similarity). D-Hiv stems from L-valine deanimation by a valine aminotransferase to 2-keto-isovaleric acid (2-Kiv), which becomes subsequently reduced by a keto-isovaleric acid reductase (KivR) to D-Hiv (By similarity). Peptide bond formation and N-methylation of the amino acid occur before three enzyme-bound dipeptidols are condensed to a hexapeptidol (By similarity). Binds 6 phosphopantetheines covalently. Antibiotic biosynthesis; enniatin 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, additional domains required for further modifications are also present (Probable). Enniatin synthetase has the C1-A1-T1-C2-A2-MT-T2a-T2b-C3 domain organization (By similarity). The precursors D-hydroxycarboxylic acids and L-amino acids become activated at the A1 and the A2 domains. N-methylation of the amino acid takes place at the MT-domain. The building blocks are transferred from one module to another by means of T-domains and are ultimately stored at the waiting position T2b. Condensation of the building blocks and final cyclization and release from the enzyme is catalyzed by the C-domains (By similarity). Enniatins have antimicrobial, antiviral and cytotoxic properties (PubMed:9170286, PubMed:16562855, PubMed:17326668). The bioactivity of enniatins can be linked to their inhibition of drug efflux pumps (PubMed:15707993). Belongs to the ATP-dependent AMP-binding enzyme family.