1ew8

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1ew8, resolution 2.2Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

ALKALINE PHOSPHATASE (E.C. 3.1.3.1) COMPLEX WITH PHOSPHONOACETIC ACID

Overview

Two high resolution crystal structures of Escherichia coli alkaline, phosphatase (AP) in the presence of phosphonate inhibitors are reported., The phosphonate compounds, phosphonoacetic acid (PAA) and, mercaptomethylphosphonic acid (MMP), bind competitively to AP with, dissociation constants of 5.5 and 0.6 mM, respectively. The structures of, the complexes of AP with PAA and MMP were refined at high resolution to, crystallographic R-values of 19.0 and 17.5%, respectively. Refinement of, the AP-inhibitor complexes was carried out using X-PLOR. The final round, of refinement was done using SHELXL-97. Crystallographic analyses of the, inhibitor complexes reveal different binding modes for the two phosphonate, compounds. The significant difference in binding constants can be, attributed to these alternative binding modes observed in the high, resolution X-ray structures. The phosphinyl group of PAA coordinates to, the active site zinc ions in a manner similar to the competitive inhibitor, and product inorganic phosphate. In contrast, MMP binds with its, phosphonate moiety directed toward solvent. Both enzyme-inhibitor, complexes exhibit close contacts, one of which has the chemical and, geometrical potential to be considered an unconventional hydrogen bond of, the type C-H...X.

About this Structure

1EW8 is a Single protein structure of sequence from Escherichia coli with ZN, PO4, SO4, MG and PAE as ligands. Active as Alkaline phosphatase, with EC number 3.1.3.1 Full crystallographic information is available from OCA.

Reference

Alternate modes of binding in two crystal structures of alkaline phosphatase-inhibitor complexes., Holtz KM, Stec B, Myers JK, Antonelli SM, Widlanski TS, Kantrowitz ER, Protein Sci. 2000 May;9(5):907-15. PMID:10850800

Page seeded by OCA on Tue Nov 20 14:22:03 2007