4o98

Crystal structure of Pseudomonas oleovorans PoOPH mutant H250I/I263W

spinqualitylabelsall models 4o98, resolution 2.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4o98 is a 2 chain structure with sequence from Pseudomonas oleovorans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.251Å Ligands: ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A0B4J186_PSEOL Publication Abstract from PubMed OPHC2 is a thermostable organophosphate (OP) hydrolase in the beta-lactamase superfamily. OPs are highly toxic synthetic chemicals with no natural analogs. How did OPHC2 acquire phosphotriesterase (PTE) activity remained unclear. In this study, an OPHC2 analogue, PoOPH was discovered from Pseudomonas oleovorans exhibiting high lactonase and esterase activities and latent PTE activity. Sequence analysis revealed conserved His250 and Ile263 and site-directed mutagenesis at these crucial residues enhanced PTE activity. The best variant PoOPHM2 carrying H250I/I263W mutations displayed 6,962- and 106-fold improvements in catalytic efficiency for methyl-parathion and ethyl-paraoxon degradation, whereas the original lactonase and esterase activities decreased dramatically. A 1.4 x 10(7) -fold of specificity inversion was achieved by only two residue substitutions. Significantly, thermostability of the variants was not compromised. Crystal structure of PoOPHM2 was determined at 2.25 A resolution and docking studies suggested that the two residues in the binding pocket determine substrate recognition. Lastly, new organophosphorus hydrolases (OPHs) were discovered using simple double mutations. Among them, PpOPHM2 from Pseudomonas putida emerged as a new promising OPH with very high activity (41.0 U mg(-1) ) toward methyl-parathion. Our results offer a first scrutiny to PTE activity evolution of OPHs in beta-lactamase superfamily and provide efficient and robust enzymes for OP detoxification. Switching a newly discovered lactonase into an efficient and thermostable phosphotriesterase by simple double mutations His250Ile/Ile263Trp.,Luo XJ, Kong XD, Zhao J, Chen Q, Zhou J, Xu JH Biotechnol Bioeng. 2014 Oct;111(10):1920-30. doi: 10.1002/bit.25272. Epub 2014, Jul 14. PMID:24771278 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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