An L-tyrosine:2-oxoglutarate aminotransferase (probably amt1) and atromentin synthetase nps3 catalyze consecutive steps to turn over L-tyrosine into atromentin, which represents the generic precursor molecule for the entire terphenylquinone and pulvinic acid family of pigments, which are widely distributed secondary metabolites in homobasidiomycetes (Probable). The first step catalyzed by amt1 converts L-tyrosine in to 4-hydroxyphenylpyruvate (4-HPP). Adenylation of two 4-HPP monomers by the nps3 adenylation (A) domain, covalent tethering of the monomers as a thioester and oxoester onto the nps3 thiolation (T) and thioesterase (TE) domains, respectively, and symmetric C-C-bond formation between two monomers catalyzed by the nps3 TE domain leads to atromentin. Follow-up products of atromentin in S.lacrymans include atromentic acid, xerocomic acid, isoxerocomic acid and variegatic acid (By similarity). 2-oxoglutarate + L-tyrosine = 3-(4-hydroxyphenyl)pyruvate + L-glutamate Secondary metabolite biosynthesis. Up-regulated upon coincubation of the fungus with the terrestrial bacteria Streptomyces iranensis, Bacillus subtilis or Pseudomonas putida. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family.