Nonribosomal peptide synthase required for the biosynthetis of epichloenin A, an extracellular siderophore that plays a crucial role in endophyte-grass symbioses (PubMed:23658520). SidN assembles epichloenin A by activating and incorporating three trans-anhydromevalonylhydroxyornithine (trans-AMHO), 1 glutamine and 4 glycine moieties (PubMed:23658520). Trans-AMHO is produced from L-ornithine via 2 steps involving a L-ornithine N(5)-monooxygenase and an AHMO-N(5)-transacylase that have still to be identified (PubMed:23658520). The third adenylation domain (A3) of sidN incorporates the hydroxamate groups of the siderophore which forms an octahedral iron complex (PubMed:23658520). The other component amino acids are assembled by sidN adenylation domains A1 and A2 (PubMed:23658520). Siderophore biosynthesis. Expression is repressed by iron (PubMed:23658520). 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 (By similarity). Each module is responsible for the recognition (via the A domain) and incorporation of a single amino acid into the growing peptide product (By similarity). 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 (By similarity). Occasionally, methyltransferase domains (responsible for amino acid methylation) are present within the NRP synthetase (By similarity). SdiN has the following architecture: A-T-C-A-T-C-A-T-C-T-C-T-C (PubMed:23658520). Leads to the accumulation of the intermediate N-5-trans-anhydromevalonyl-N-5-hydroxyornithine (trans-AMHO), displays sensitivity to oxidative stress and shows deficiencies in both polarized hyphal growth and sporulation (PubMed:23658520). Changes its interaction with the plant Lolium perenne from mutually beneficial to antagonistic (PubMed:23658520). Belongs to the NRP synthetase family.