Nonribosomal peptide synthetase that mediates the biosynthesis of atromentin (PubMed:29305695). AtrA first activates 4-hydroxyphenylpyruvate (HPPA) through its A domain to AMP-HPPA (PubMed:29305695). The HPPA unit is then loaded to the T domain and eventually transferred to the TE domain (PubMed:29305695). Another HPPA unit is then loaded onto the T domain (PubMed:29305695). The TE domain then catalyzes the condensation of the two HPPA units and the release of atromentin via cyclization (PubMed:29305695). 2 3-(4-hydroxyphenyl)pyruvate + H(+) = atromentin + 2 H2O AtrA has an A-T-TE domain architecture (Probable). The adenylation (A) domain recognizes and activates the aryl acid substrates, and loads them onto the thiolation (T) domain (Probable). The thioesterase (TE) domain shares the missing condensation (C) domain function, and is responsible for condensation and final product release (Probable). Belongs to the NRP synthetase family.