Isomerase that catalyzes the condensation of two molecules of trans-2,3-dihydro-3-hydroxyanthranilic acid (DHHA) into the phenazine ring system. The final product is not yet known. (5S,6S)-6-amino-5-hydroxycyclohexa-1,3-diene-1-carboxyate = (1R,6S)-6-amino-5-oxocyclohex-2-ene-1-carboxylate Antibiotic biosynthesis; phenazine biosynthesis. Belongs to the PhzF family.