3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate active site structure analysis, substrate binding, H295 and E365 are involved in substrate orientation and stabilization of the transition state, oxygen binding and bridging at the metal ion center, overview, reaction mechanism 666742 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate Asn91 and His92 are active site residues which interact with the loop residue Asp146, this interaction and substrate positioning by His92 is important for catalysis, Asn91 ia a ligand to the divalent metal of the mixed-valent di-iron center 664888 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate detailed structure-based catalytic mechanism 666066 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate formation of a covalent phosphoryl-enzyme intermediate, kinetic pattern of a pseudo uni-bi hydrolytic two-step reaction mechanism 134688, 134689 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate modelling of substrate binding in the active site -, 664223 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate regioselective and stereospecific phosphorylation of diverse substrates by the acid phosphatase from Shigella flexneri and Salmonella enterica 663565 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate the dephosphorylation of phosphotyrosine by PAP is a two-step process: the first step involves the transfer of a phosphate group from the substrate to the histidine (His12). A number of quantum models are constructed containing various residues that are thought to play a role in the mechanism. In all these models, the transition state displays an associative character. The transition state is stabilized by three active site arginines (Arg11, Arg15, and Arg79), two of which belong to the conserved motif (RHGXRXP). His12 can act as a nucleophile. The enzyme is further characterized by a His257-Asp258 motif. Asp258 acts as a proton donor which becomes protonated when the substrate enters the binding pocket. The transfer of a proton from Asp258 to the leaving group is possibly mediated by a water molecule in the active site. The importance of His257 in lowering the energy barrier for the nucleophilic attack is shown 692774 3.1.3.2 a phosphate monoester + H2O = an alcohol + phosphate the enzyme is a Zn-metallophosphatase containing an essential zinc ion in the active site 665856