5h3h
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[5h3h]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Exiguobacterium_antarcticum_B7 Exiguobacterium antarcticum B7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5H3H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5H3H FirstGlance]. <br> | <table><tr><td colspan='2'>[[5h3h]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Exiguobacterium_antarcticum_B7 Exiguobacterium antarcticum B7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5H3H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5H3H FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=F50:ETHANEPEROXOIC+ACID'>F50</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=F50:ETHANEPEROXOIC+ACID'>F50</scene></td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5h3h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5h3h OCA], [https://pdbe.org/5h3h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5h3h RCSB], [https://www.ebi.ac.uk/pdbsum/5h3h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5h3h ProSAT]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5h3h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5h3h OCA], [https://pdbe.org/5h3h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5h3h RCSB], [https://www.ebi.ac.uk/pdbsum/5h3h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5h3h ProSAT]</span></td></tr> | ||
</table> | </table> | ||
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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. | 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<ref>PMID:28125606</ref> | + | 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<ref>PMID:28125606</ref> |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
Current revision
Esterase (EaEST) from Exiguobacterium antarcticum
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