Dephosphorylates etk. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Belongs to the low molecular weight phosphotyrosine protein phosphatase family. In E.coli K12 / MG1655 and K12 / W3110 this operon is silenced by an IS1D insertion in the promoter region.