Nonribosomal peptide synthase; part of the inp gene cluster that mediates the biosynthesis of fellutamide B, a mycotoxin that acts as a proteasome inhibitor (PubMed:18804170, PubMed:20952652, PubMed:27294372). In the first step of fellutabmide B biosynthesis inpC activates 3-hydroxydodecanoic acid to generate 3-hydroxydodecanoyl-AMP that is then loaded onto the T0 domain of inpB (PubMed:27294372). The 3-hydroxydodecanoyl-S-phosphopantetheinyl-T0 is sequentially extended with L-Asn and L-Gln by the two CAT modules of inpB (PubMed:27294372). The linear lipodipeptide from inpB is then transferred onto inpA for the addition of the third amino acid, L-Leu (PubMed:27294372). Reductive releasing of the lipotripeptide by the TE domain of inpA produces (2S)-fellutamide B (PubMed:27294372). InpF might be involved in the release and transfer of the lipodipeptide from inpB to inpA (PubMed:27294372). The inp cluster-encoded proteasome subunit inpE confers resistance to internally produced fellutamides (PubMed:27294372). The MFS efflux transporter inpD may contribute to fellutamide resistance as well (PubMed:27294372). Secondary metabolite biosynthesis. Expression is positively regulated by the secondary metabolism cross-pathway regulator scpR (PubMed:20952652). 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). InpB has the following architecture: T0-C-A-T-C-A-T (PubMed:18804170). Eliminates the production of fellutamides (PubMed:27294372). Does not impair the production of asperfuranone (PubMed:20952652). Belongs to the NRP synthetase family.