Involved in the naphthalene catabolic pathway. Catalyzes the reversible glutathione-dependent isomerization of 2-hydroxychromene-2-carboxylate (HCCA) to trans-O-hydroxybenzylidenepyruvate (THBPA) (Probable). 2-hydroxychromene-2-carboxylate = (3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate Aromatic compound metabolism; naphthalene degradation. DoxH and doxJ encode different enzymes that may have interchangeable functions. Encoded on an unnamed 75 kb plasmid. Belongs to the GST superfamily. NadH family. Extended N-terminus.