Involved in the naphthalene upper catabolic pathway. Catalyzes the transformation of trans-O-hydroxybenzylidenepyruvate (THBPA) to salicylaldehyde and pyruvate. The reaction is reversible (Probable). (3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate + H2O = pyruvate + salicylaldehyde Aromatic compound metabolism; naphthalene degradation. Encoded on an unnamed 75 kb plasmid. Belongs to the DapA family.