Amino acid sequence of catechol 1,2-dioxygenase (pyrocatechase) isozyme alpha alpha from Pseudomonas arvilla C-1.

Catechol 1,2-dioxygenase catalyzes the oxygenative ring cleavage of catechol to form cis,cis-muconic acid, and contains a ferric form of iron as its sole cofactor. Pseudomonas arvilla C-1 contains three isozymes of the enzyme, alpha alpha, alpha beta, and beta beta [C. Nakai et al. (1990) J. Biol. Chem. 265, 660-665]. We have determined the amino acid sequence of the alpha alpha isozyme by direct analysis. The sequence shared 77% homology with isozyme beta beta, and had conserved tyrosyl and histidyl residues which are thought to be involved in the binding of ferric ion.