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| | ==Crystal structure of the extended-spectrum beta-lactamase OXA-145== | | ==Crystal structure of the extended-spectrum beta-lactamase OXA-145== |
| - | <StructureSection load='4yin' size='340' side='right' caption='[[4yin]], [[Resolution|resolution]] 2.30Å' scene=''> | + | <StructureSection load='4yin' size='340' side='right'caption='[[4yin]], [[Resolution|resolution]] 2.30Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4yin]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_aeruginosus"_(schroeter_1872)_trevisan_1885 "bacillus aeruginosus" (schroeter 1872) trevisan 1885]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4YIN OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4YIN FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4yin]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4YIN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4YIN FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FLC:CITRATE+ANION'>FLC</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]] 2.3Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">oxa145 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=287 "Bacillus aeruginosus" (Schroeter 1872) Trevisan 1885])</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FLC:CITRATE+ANION'>FLC</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=4yin FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4yin OCA], [https://pdbe.org/4yin PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4yin RCSB], [https://www.ebi.ac.uk/pdbsum/4yin PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4yin 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=4yin FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4yin OCA], [http://pdbe.org/4yin PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4yin RCSB], [http://www.ebi.ac.uk/pdbsum/4yin PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4yin ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| - | <div style="background-color:#fffaf0;">
| + | == Function == |
| - | == Publication Abstract from PubMed == | + | [https://www.uniprot.org/uniprot/C0LZL5_PSEAI C0LZL5_PSEAI] |
| - | OBJECTIVES: We previously described extended-spectrum oxacillinase OXA-145 from Pseudomonas aeruginosa, which differs from narrow-spectrum OXA-35 by loss of Leu-155. The deletion results in loss of benzylpenicillin hydrolysis and acquisition of activity against ceftazidime. We report the crystal structure of OXA-145 and provide the basis of its switch in substrate specificity. METHODS: OXA-145 variants were generated by site-directed mutagenesis and purified to homogeneity. The crystal structure of OXA-145 was determined and molecular dynamics simulations were performed. Kinetic parameters were investigated in the absence and in the presence of sodium hydrogen carbonate (NaHCO3) for representative substrates. RESULTS: The structure of OXA-145 was obtained at a resolution of 2.3 A and its superposition with that of OXA-10 showed that Trp-154 was shifted by 1.8 A away from the catalytic Lys-70, which was not N-carboxylated. Addition of NaHCO3 significantly increased the catalytic efficiency against penicillins, but not against ceftazidime. The active-site cavity of OXA-145 was larger than that of OXA-10, which may favour the accommodation of large molecules such as ceftazidime. Molecular dynamics simulations of OXA-145 in complex with ceftazidime revealed two highly coordinated water molecules on the alpha- or beta-face of the acyl ester bond, between Ser-67 and ceftazidime, which could be involved in the catalytic process. CONCLUSIONS: Deletion of Leu-155 resulted in inefficient positioning of Trp-154, leading to a non-carboxylated Lys-70 and thus to loss of hydrolysis of the penicillins. Ceftazidime hydrolysis could be attributed to enlargement of the active site and to a catalytic mechanism independent of the carboxylated Lys-70.
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| - | Structural insights into the loss of penicillinase and the gain of ceftazidimase activities by OXA-145 beta-lactamase in Pseudomonas aeruginosa.,Meziane-Cherif D, Bonnet R, Haouz A, Courvalin P J Antimicrob Chemother. 2016 Feb;71(2):395-402. doi: 10.1093/jac/dkv375. Epub, 2015 Nov 14. PMID:26568564<ref>PMID:26568564</ref>
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| - | </div>
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| - | <div class="pdbe-citations 4yin" style="background-color:#fffaf0;"></div>
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| | ==See Also== | | ==See Also== |
| - | *[[Beta-lactamase|Beta-lactamase]] | + | *[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] |
| - | == References ==
| + | |
| - | <references/>
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Beta-lactamase]] | + | [[Category: Large Structures]] |
| - | [[Category: Bonnet, R]] | + | [[Category: Pseudomonas aeruginosa]] |
| - | [[Category: Courvalin, P]] | + | [[Category: Bonnet R]] |
| - | [[Category: Haouz, A]] | + | [[Category: Courvalin P]] |
| - | [[Category: Meziane-Cherif, D]] | + | [[Category: Haouz A]] |
| - | [[Category: Antibiotic resistance]]
| + | [[Category: Meziane-Cherif D]] |
| - | [[Category: Class d]]
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| - | [[Category: Extended-spectrum beta-lactamase]]
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| - | [[Category: Hydrolase]]
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| - | [[Category: Oxacillinase]]
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