Kinetic characterization of the Escherichia coli oligopeptidase A (OpdA) and the role of the Tyr(607) residue.

Oligopeptidase A (OpdA) belongs to the M3A subfamily of bacterial peptidases with catalytic and structural properties similar to mammalian thimet-oligopeptidase (TOP) and neurolysin (NEL). The three enzymes have four conserved Tyr residues on a flexible loop in close proximity to the catalytic site. In OpdA, the flexible loop is formed by residues 600-614 ((600)SHIFAGGYAAGYYSY(614)).