Arylacetonitrilase which is capable of hydrolyzing indole-3-acetonitrile (IAN) to the plant hormone indole-3-acetate (IAA), and allows the plant pathogenic bacterium to use IAN as a sole nitrogen source. Is also able to hydrolyze phenylpropionitrile (PPN), allowing the use of this compound as a sole nitrogen source. This enzyme may represent an additional mechanism for IAA biosynthesis or may be used to degrade and assimilate aldoximes and nitriles produced during host plant secondary metabolism. a nitrile + 2 H2O = a carboxylate + NH4(+) (indol-3-yl)acetonitrile + 2 H2O = (indol-3-yl)acetate + NH4(+) 2 H2O + phenylpropanonitrile = 3-phenylpropanoate + NH4(+) Cells lacking this gene are unable to grow in medium in which the sole nitrogen source is either indole-3-acetonitrile (IAN) or phenylpropionitrile (PPN). Their growth is also moderately reduced in medium with ammonia as the nitrogen source; one possible explanation for this phenotype is that the disruption of Psyr_0007 results in the accumulation of endogenous nitriles that can no longer be degraded and which inhibit bacterial growth. Belongs to the carbon-nitrogen hydrolase superfamily. Nitrilase family.