Hydrolytic enzyme with a broad substrate specificity acting on phosphate diesters and phosphonate monoesters (PubMed:8824203, PubMed:20133613). Hydrolyzes phosphate mono- and triesters, sulfate monoesters and sulfonate monoesters (PubMed:20133613). Hydrolyzes glyphosate monoesters. Does not hydrolyze DNA or cGMP (PubMed:8824203). Hydrolyzes glyceryl glyphosate, but this substrate has a much lower affinity than the glyphosate monoesters (PubMed:8824203, PubMed:8771792). Mn(2+) is probably the active metal ion. Other metals such as Zn(2+), Ca(2+) and Fe(2+) can also act as cofactors. Anions including Cl(-) and CH3COO(-), and SO4(2-) salts stimulate activity 20-40% at 100 mM. kcat is 0.0021 sec(-1) with phenyl phosphate as substrate. kcat is 0.077 sec(-1) with 4-nitrophenyl phosphate as substrate. kcat is 2.12 sec(-1) with diphenyl phosphate as substrate. kcat is 5.8 sec(-1) with p-nitrophenyl ethyl phosphate as substrate. kcat is 0.00037 sec(-1) with paraoxon as substrate. kcat is 1.58 sec(-1) with phenyl phenylphosphonate as substrate. kcat is 2.73 sec(-1) with p-nitrophenyl phenylphosphonate as substrate. kcat is 0.001 sec(-1) with phenyl sulfate as substrate. kcat is 0.4 sec(-1) with p-nitrophenyl sulfate as substrate. kcat is 0.007 sec(-1) with phenyl phenylsulfonate as substrate. kcat is 0.12 sec(-1) with p-nitrophenyl phenylsulfonate as substrate (PubMed:20133613). kcat is 28 min(-1) with glyceryl glyphosate as substrate. kcat is 400 min(-1) with p-nitrophenyl phenylphosphonate as substrate. kcat is 620 min(-1) with bis(p-nitrophenyl) phosphate as substrate. kcat is 89 min(-1) with p-nitrophenyl thymidine 5'-monophosphate as substrate (PubMed:8824203). Optimum pH is 9.0. Homotetramer. The conversion to 3-oxoalanine (also known as C-formylglycine, FGly), of a serine or cysteine residue in prokaryotes and of a cysteine residue in eukaryotes, is critical for catalytic activity (By similarity). Phosphate triester hydrolytic activity is retained with unmodified cysteine acting as a nucleophile (PubMed:20133613). Has potential application in plant genetics as a heterologous conditional lethal gene useful for cell ablation and negative (counter) selection. Belongs to the alkaline phosphatase superfamily. There is conflicting evidence for Zn(2+) acting as an active metal ion. According to one report, it inhibits the phosphonate ester hydrolase activity (PubMed:8824203). According to another report, it acts as a cofactor (PubMed:20133613).