Can cleave 4-methylcatechol at lower rates than catechol, but has no activity with 3-methylcatechol, 4-chlorocatechol, 4-carboxycatechol or hydroxyquinol. catechol + O2 = cis,cis-muconate + 2 H(+) Binds 1 Fe(3+) ion per subunit. Inhibited by Ag(+), Cu(+), Hg(2+) and Pb(2+). Optimum pH is 8.0. Active from pH 7.0 to 9.0. Optimum temperature is 25 degrees Celsius. Stable at temperatures lower than 40 degrees Celsius. Aromatic compound metabolism; beta-ketoadipate pathway; 5-oxo-4,5-dihydro-2-furylacetate from catechol: step 1/3. Homodimer. By phenol. Belongs to the intradiol ring-cleavage dioxygenase family.