5h3h

Esterase (EaEST) from Exiguobacterium antarcticum

spinqualitylabelsall models 5h3h, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5h3h is a 2 chain structure with sequence from Exiguobacterium antarcticum B7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: F50 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function K0ACL0_EXIAB Publication Abstract from PubMed A novel microbial esterase, EaEST, from a psychrophilic bacterium Exiguobacterium antarcticum B7, was identified and characterized. To our knowledge, this is the first report describing structural analysis and biochemical characterization of an esterase isolated from the genus Exiguobacterium. Crystal structure of EaEST, determined at a resolution of 1.9 A, showed that the enzyme has a canonical alpha/beta hydrolase fold with an alpha-helical cap domain and a catalytic triad consisting of Ser96, Asp220, and His248. Interestingly, the active site of the structure of EaEST is occupied by a peracetate molecule, which is the product of perhydrolysis of acetate. This result suggests that EaEST may have perhydrolase activity. The activity assay showed that EaEST has significant perhydrolase and esterase activity with respect to short-chain p-nitrophenyl esters (</=C8), naphthyl derivatives, phenyl acetate, and glyceryl tributyrate. However, the S96A single mutant had low esterase and perhydrolase activity. Moreover, the L27A mutant showed low levels of protein expression and solubility as well as preference for different substrates. On conducting an enantioselectivity analysis using R- and S-methyl-3-hydroxy-2-methylpropionate, a preference for R-enantiomers was observed. Surprisingly, immobilized EaEST was found to not only retain 200% of its initial activity after incubation for 1 h at 80 degrees C, but also retained more than 60% of its initial activity after 20 cycles of reutilization. This research will serve as basis for future engineering of this esterase for biotechnological and industrial applications. Crystal Structure and Functional Characterization of an Esterase (EaEST) from Exiguobacterium antarcticum.,Lee CW, Kwon S, Park SH, Kim BY, Yoo W, Ryu BH, Kim HW, Shin SC, Kim S, Park H, Kim TD, Lee JH PLoS One. 2017 Jan 26;12(1):e0169540. doi: 10.1371/journal.pone.0169540. , eCollection 2017. PMID:28125606 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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