1jsr

CRYSTAL STRUCTURE OF ERWINIA CHRYSANTHEMI L-ASPARAGINASE COMPLEXED WITH 6-HYDROXY-L-NORLEUCINE

spinqualitylabelsall models 1jsr, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1jsr is a 4 chain structure with sequence from Dickeya chrysanthemi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.7Å Ligands: 1PE, GOL, LDO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ASPG_DICCH Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The structures of Erwinia chrysanthemi L-asparaginase (ErA) complexed with the L- and D-stereoisomers of the suicide inhibitor, 6-diazo-5-oxy-norleucine, have been solved using X-ray crystallography and refined with data extending to 1.7 A. The distances between the Calpha atoms of the inhibitor molecules and the hydroxyl oxygen atoms of Thr-15 and Tyr-29 (1.20 and 1.60 A, respectively) clearly indicate the presence of covalent bonds between these moieties, confirming the nucleophilic role of Thr-15 during the first stage of enzymatic reactions and also indicating direct involvement of Tyr-29. The factors responsible for activating Tyr-29 remain unclear, although some structural changes around Ser-254', Asp-96, and Glu-63, common to both complexes, suggest that those residues play a function. The role of Glu-289' as the activator of Tyr-29, previously postulated for the closely related Pseudomonas 7A L-glutaminase-asparaginase, is not confirmed in this study, due to the lack of interactions between these residues in these complexes and in holoenzymes. The results reported here are consistent with previous reports that mutants of Escherichia coli L-asparaginase lacking Glu-289 remain catalytically active and prove the catalytic roles of both Thr-15 and Tyr-29, while still leaving open the question of the exact mechanism resulting in the unusual chemical properties of these residues. Do bacterial L-asparaginases utilize a catalytic triad Thr-Tyr-Glu?,Aghaiypour K, Wlodawer A, Lubkowski J Biochim Biophys Acta. 2001 Dec 17;1550(2):117-28. PMID:11755201 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Asparaginase 3D structures

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