Bacteria such as Pseudomonas diminuta harbor a plasmid that carries the gene for aryldialkylphosphatase (EC220.127.116.11). This enzyme has attracted interest because of its potential use in the detoxification of chemical waste and warfare agents and its ability to degrade agricultural pesticides such as parathion. It acts specifically on synthetic organophosphate triesters and phosphorofluoridates. It does not seem to have a natural occurring substrate and may thus have optimally evolved for utilizing paraoxon.
Aryldialkylphosphatase belongs to a family of enzymes that possess a binuclear zinc metal centre at their active site. The two zinc ions are coordinated by six different residues, six of which being histidines.