3m2k: Difference between revisions
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==Crystal Structure of fluorescein-labeled Class A -beta lactamase PenP in complex with cefotaxime== | ==Crystal Structure of fluorescein-labeled Class A -beta lactamase PenP in complex with cefotaxime== | ||
<StructureSection load='3m2k' size='340' side='right' caption='[[3m2k]], [[Resolution|resolution]] 3.50Å' scene=''> | <StructureSection load='3m2k' size='340' side='right'caption='[[3m2k]], [[Resolution|resolution]] 3.50Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[3m2k]] is a 2 chain structure with sequence from [ | <table><tr><td colspan='2'>[[3m2k]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/"clostridium_licheniforme"_weigmann_1898 "clostridium licheniforme" weigmann 1898]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3M2K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3M2K FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CEF:CEFOTAXIME,+C3+CLEAVED,+OPEN,+BOUND+FORM'>CEF</scene></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CEF:CEFOTAXIME,+C3+CLEAVED,+OPEN,+BOUND+FORM'>CEF</scene></td></tr> | ||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3ly3|3ly3]], [[3ly4|3ly4]], [[3m2j|3m2j]]</td></tr> | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[3ly3|3ly3]], [[3ly4|3ly4]], [[3m2j|3m2j]]</div></td></tr> | ||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">penP ([ | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">penP ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1402 "Clostridium licheniforme" Weigmann 1898])</td></tr> | ||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Beta-lactamase Beta-lactamase], with EC number [https://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'>[ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3m2k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3m2k OCA], [https://pdbe.org/3m2k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3m2k RCSB], [https://www.ebi.ac.uk/pdbsum/3m2k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3m2k ProSAT]</span></td></tr> | ||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
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==See Also== | ==See Also== | ||
*[[Beta-lactamase|Beta-lactamase | *[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
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[[Category: Clostridium licheniforme weigmann 1898]] | [[Category: Clostridium licheniforme weigmann 1898]] | ||
[[Category: Beta-lactamase]] | [[Category: Beta-lactamase]] | ||
[[Category: Large Structures]] | |||
[[Category: Leung, Y C]] | [[Category: Leung, Y C]] | ||
[[Category: Wong, W T]] | [[Category: Wong, W T]] | ||
Revision as of 16:43, 4 May 2022
Crystal Structure of fluorescein-labeled Class A -beta lactamase PenP in complex with cefotaximeCrystal Structure of fluorescein-labeled Class A -beta lactamase PenP in complex with cefotaxime
Structural highlights
Publication Abstract from PubMedBACKGROUND: beta-lactamase conjugated with environment-sensitive fluorescein molecule to residue 166 on the Omega-loop near its catalytic site is a highly effective biosensor for beta-lactam antibiotics. Yet the molecular mechanism of such fluorescence-based biosensing is not well understood. RESULTS: Here we report the crystal structure of a Class A beta-lactamase PenP from Bacillus licheniformis 749/C with fluorescein conjugated at residue 166 after E166C mutation, both in apo form (PenP-E166Cf) and in covalent complex form with cefotaxime (PenP-E166Cf-cefotaxime), to illustrate its biosensing mechanism. In the apo structure the fluorescein molecule partially occupies the antibiotic binding site and is highly dynamic. In the PenP-E166Cf-cefatoxime complex structure the binding and subsequent acylation of cefotaxime to PenP displaces fluorescein from its original location to avoid steric clash. Such displacement causes the well-folded Omega-loop to become fully flexible and the conjugated fluorescein molecule to relocate to a more solvent exposed environment, hence enhancing its fluorescence emission. Furthermore, the fully flexible Omega-loop enables the narrow-spectrum PenP enzyme to bind cefotaxime in a mode that resembles the extended-spectrum beta-lactamase. CONCLUSIONS: Our structural studies indicate the biosensing mechanism of a fluorescein-labelled beta-lactamase. Such findings confirm our previous proposal based on molecular modelling and provide useful information for the rational design of beta-lactamase-based biosensor to detect the wide spectrum of beta-lactam antibiotics. The observation of increased Omega-loop flexibility upon conjugation of fluorophore may have the potential to serve as a screening tool for novel beta-lactamase inhibitors that target the Omega-loop and not the active site. Structural studies of the mechanism for biosensing antibiotics in a fluorescein-labeled beta-lactamase.,Wong WT, Au HW, Yap HK, Leung YC, Wong KY, Zhao Y BMC Struct Biol. 2011 Mar 28;11:15. doi: 10.1186/1472-6807-11-15. PMID:21443768[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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