A high resolution crystal structure of Escherichia coli alkaline phosphatase in the presence of vanadate has been refined to 1.9 A resolution. The vanadate ion takes on a trigonal bipyramidal geometry and is covalently bound by the active site serine nucleophile ...
A high resolution crystal structure of Escherichia coli alkaline phosphatase in the presence of vanadate has been refined to 1.9 A resolution. The vanadate ion takes on a trigonal bipyramidal geometry and is covalently bound by the active site serine nucleophile. A coordinated water molecule occupies the axial position opposite the serine nucleophile, whereas the equatorial oxygen atoms of the vanadate ion are stabilized by interactions with both Arg-166 and the zinc metal ions of the active site. This structural complex supports the in-line displacement mechanism of phosphomonoester hydrolysis by alkaline phosphatase and provides a model for the proposed transition state in the enzyme-catalyzed reaction.
Related Citations:
Trapping and Visualization of a Covalent Enzyme-Phosphate Intermediate Murphy, J.E., Stec, B., Ma, L., Kantrowitz, E.R. (1997) Nat Struct Biol 4: 618
Reaction Mechanism of Alkaline Phosphatase Based on Crystal Structures. Two- Metal Ion Catalysis Kim, E.E., Wyckoff, H.W. (1991) J Mol Biol 218: 449
Organizational Affiliation:
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02167, USA.
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