Catechol O-methyltransferase that can use various catechol-like compounds such as gallic acid (GA), 3,4-dihydroxy-5-methoxy-benzoic acid (5OMeBA), protocatechuic acid (PCA), 3,4-dihydroxy-benzaldehyde (DHA), dopamine, caffeic acid (CA), luteolin, quercetin, and 5-hydroxyuridine. a catechol + S-adenosyl-L-methionine = a guaiacol + H(+) + S-adenosyl-L-homocysteine Inhibited by EDTA. kcat is 0.080 min(-1) with 5OMeBA as substrate. kcat is 0.22 min(-1) with PCA as substrate. kcat is 0.43 min(-1) with CA as substrate. Homodimer. Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-dependent O-methyltransferase family.