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| | ==Crystal structure of beta-lactamase PenP mutant-E166H== | | ==Crystal structure of beta-lactamase PenP mutant-E166H== |
| - | <StructureSection load='5ghx' size='340' side='right' caption='[[5ghx]], [[Resolution|resolution]] 1.24Å' scene=''> | + | <StructureSection load='5ghx' size='340' side='right'caption='[[5ghx]], [[Resolution|resolution]] 1.24Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5ghx]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GHX OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5GHX FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5ghx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GHX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5GHX FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</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]] 1.24Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5ghy|5ghy]], [[5ghz|5ghz]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</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-lactamase Beta-lactamase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.6 3.5.2.6] </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=5ghx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ghx OCA], [https://pdbe.org/5ghx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ghx RCSB], [https://www.ebi.ac.uk/pdbsum/5ghx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ghx 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=5ghx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ghx OCA], [http://pdbe.org/5ghx PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5ghx RCSB], [http://www.ebi.ac.uk/pdbsum/5ghx PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5ghx ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| - | <div style="background-color:#fffaf0;">
| + | == Function == |
| - | == Publication Abstract from PubMed == | + | [https://www.uniprot.org/uniprot/BLAC_BACLI BLAC_BACLI] |
| - | beta-Lactamases confer resistance to beta-lactam-based antibiotics. There is great interest in understanding their mechanisms to enable the development of beta-lactamase-specific inhibitors. The mechanism of class A beta-lactamases has been studied extensively, revealing Lys-73 and Glu-166 as general bases that assist the catalytic residue Ser-70. However, the specific roles of these two residues within the catalytic cycle remain not fully understood. To help resolve this, we first identified an E166H mutant that is functional but is kinetically slow. We then carried out time-resolved crystallographic study of a full cycle of the catalytic reaction. We obtained structures that represent apo, ES*-acylation, and ES*-deacylation states and analyzed the conformational changes of His-166. The "in" conformation in the apo structure allows His-166 to form a hydrogen bond with Lys-73. The unexpected "flipped-out" conformation of His-166 in the ES*-acylation structure was further examined by molecular dynamics simulations, which suggested deprotonated Lys-73 serving as the general base for acylation. The "revert-in" conformation in the ES*-deacylation structure aligns His-166 toward the water molecule that hydrolyzes the acyl adduct. Finally, when the acyl adduct is fully hydrolyzed, His-166 rotates back to the "in" conformation of the apo-state, restoring the Lys-73/His-166 interaction. Using His-166 as surrogate, our study identifies distinct conformational changes within the active site during catalysis. We suggest that the native Glu-166 executes similar changes in a less constricted way. Taken together, this structural series improves our understanding of beta-lactam hydrolysis in this important class of enzymes.
| + | |
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| - | Crystallographic Snapshots of Class A beta-Lactamase Catalysis Reveal Structural Changes That Facilitate beta-Lactam Hydrolysis.,Pan X, He Y, Lei J, Huang X, Zhao Y J Biol Chem. 2017 Mar 10;292(10):4022-4033. doi: 10.1074/jbc.M116.764340. Epub, 2017 Jan 18. PMID:28100776<ref>PMID:28100776</ref>
| + | ==See Also== |
| - | | + | *[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] |
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| + | |
| - | </div>
| + | |
| - | <div class="pdbe-citations 5ghx" style="background-color:#fffaf0;"></div>
| + | |
| - | == References ==
| + | |
| - | <references/>
| + | |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Beta-lactamase]] | + | [[Category: Bacillus licheniformis]] |
| - | [[Category: Pan, X]] | + | [[Category: Large Structures]] |
| - | [[Category: Zhao, Y]] | + | [[Category: Pan X]] |
| - | [[Category: Hydrolase]] | + | [[Category: Zhao Y]] |
