2-hydroxychromene-2-carboxylate isomerase (, HCCA isomerase, 2HC2CA isomerase, 2-hydroxychromene-2-carboxylic acid isomerase) is an enzyme with systematic name 2-hydroxy-2H-chromene-2-carboxylate---(3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate isomerase. This enzyme catalyses the following chemical reaction
This enzyme is involved in naphthalene degradation.