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| | <StructureSection load='5i3d' size='340' side='right'caption='[[5i3d]], [[Resolution|resolution]] 2.16Å' scene=''> | | <StructureSection load='5i3d' size='340' side='right'caption='[[5i3d]], [[Resolution|resolution]] 2.16Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5i3d]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Sacs2 Sacs2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5I3D OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5I3D FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5i3d]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_solfataricus_P2 Saccharolobus solfataricus P2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5I3D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5I3D FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=PE8:3,6,9,12,15,18,21-HEPTAOXATRICOSANE-1,23-DIOL'>PE8</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]] 2.16Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">lacS, SSO3019 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=273057 SACS2])</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=PE8:3,6,9,12,15,18,21-HEPTAOXATRICOSANE-1,23-DIOL'>PE8</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-galactosidase Beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.23 3.2.1.23] </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=5i3d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5i3d OCA], [https://pdbe.org/5i3d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5i3d RCSB], [https://www.ebi.ac.uk/pdbsum/5i3d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5i3d ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5i3d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5i3d OCA], [http://pdbe.org/5i3d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5i3d RCSB], [http://www.ebi.ac.uk/pdbsum/5i3d PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5i3d ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/BGAL_SACS2 BGAL_SACS2] |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Beta-galactosidase]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Sacs2]] | + | [[Category: Saccharolobus solfataricus P2]] |
| - | [[Category: Davis, B D]] | + | [[Category: Davis BD]] |
| - | [[Category: Fordham-Skelton, A]] | + | [[Category: Fordham-Skelton A]] |
| - | [[Category: Hancock, S M]] | + | [[Category: Hancock SM]] |
| - | [[Category: Iglesias-Fernandez, J]] | + | [[Category: Iglesias-Fernandez J]] |
| - | [[Category: Lee, S S]] | + | [[Category: Lee SS]] |
| - | [[Category: McAuley, K E]] | + | [[Category: McAuley KE]] |
| - | [[Category: Rovira, C]] | + | [[Category: Rovira C]] |
| - | [[Category: Glycosidase]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| Structural highlights
Function
BGAL_SACS2
Publication Abstract from PubMed
SNi-like mechanisms, which involve front-face leaving group departure and nucleophile approach, have been observed experimentally and computationally in chemical and enzymatic substitution at alpha-glycosyl electrophiles. Since SNi-like, SN1 and SN2 substitution pathways can be energetically comparable, engineered switching could be feasible. Here, engineering of Sulfolobus solfataricus beta-glycosidase, which originally catalyzed double SN2 substitution, changed its mode to SNi-like. Destruction of the first SN2 nucleophile through E387Y mutation created a beta-stereoselective catalyst for glycoside synthesis from activated substrates, despite lacking a nucleophile. The pH profile, kinetic and mutational analyses, mechanism-based inactivators, X-ray structure and subsequent metadynamics simulations together suggest recruitment of substrates by pi-sugar interaction and reveal a quantum mechanics-molecular mechanics (QM/MM) free-energy landscape for the substitution reaction that is similar to those of natural, SNi-like glycosyltransferases. This observation of a front-face mechanism in a beta-glycosyltransfer enzyme highlights that SNi-like pathways may be engineered in catalysts with suitable environments and suggests that 'beta-SNi' mechanisms may be feasible for natural glycosyltransfer enzymes.
A front-face 'SNi synthase' engineered from a retaining 'double-SN2' hydrolase.,Iglesias-Fernandez J, Hancock SM, Lee SS, Khan M, Kirkpatrick J, Oldham NJ, McAuley K, Fordham-Skelton A, Rovira C, Davis BG Nat Chem Biol. 2017 Jun 12. doi: 10.1038/nchembio.2394. PMID:28604696[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Iglesias-Fernandez J, Hancock SM, Lee SS, Khan M, Kirkpatrick J, Oldham NJ, McAuley K, Fordham-Skelton A, Rovira C, Davis BG. A front-face 'SNi synthase' engineered from a retaining 'double-SN2' hydrolase. Nat Chem Biol. 2017 Jun 12. doi: 10.1038/nchembio.2394. PMID:28604696 doi:http://dx.doi.org/10.1038/nchembio.2394
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