O-methyltransferase; part of the gene cluster that mediates the biosynthesis of the aspergillicins A and F, 2 cryptic cyclic hexa-depsipeptides (PubMed:31117395). The hexamodular NRPS agiA catalyzes the condensation of the six amino acid residues including N-Me-L-O-Me-tyrosine, L-proline 1, L-proline 2, D-isoleucine, O-acetyl-threonine, and L-isoleucine (PubMed:31117395). The starting condensation domain (C1) of agiA probably loads acetyl-CoA which is condensed on the N-terminus of threonine by the first module to yield O-acetyl-threonine (PubMed:26273902). The second module then loads L-isoleucine. The epimerase (E) domain on module 2 is probably involved in the formation of the D-isoleucine moiety (PubMed:26273902). Modules 3 and 4 further load 2 successive L-prolines (PubMed:26273902). Module 5 is then involved in the condensation of O-Me-L-tyrosine produced by the O-methyltransferase agiB and the N-methyl transferase (NMeT) domain on module 5 probably catalyzes the N-methylation to yield the N-Me-L-O-Me-tyrosine moiety (PubMed:26273902). The A domain of module 5 loads preferentially O-Me-L-tyrosine, but it can also accept L-phenylalanine, which leads to the production of aspergillicin G (PubMed:26273902). Module 6 then loads the last residue, L-isoleucine (PubMed:26273902). The C-terminal thiolesterase (TE) domain probably cyclizes the peptide using the hydroxy group from threonine to form the cyclic depsipeptide (PubMed:26273902). Secondary metabolite biosynthesis. Impairs the production of aspergillicins A and F but accumulates aspergillicins C and G. Aspergillicins show innate immunity-modulating activity. Innate immunity is a good pharmaceutical target for the development of immune regulators to suppress unwanted immune responses, such as septic shock, inflammatory diseases, and autoimmune diseases. The innate immune system also provides targets for the development of agents that stimulate protective immune responses toward some diseases, such as infections with pathogenic organisms and cancer. Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-independent O-methyltransferase family.