View source for 6qwd


==Crystal structure of KPC-3==
<StructureSection load='6qwd' size='340' side='right'caption='[[6qwd]], [[Resolution|resolution]] 1.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6qwd]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Klebsiella_pneumoniae Klebsiella pneumoniae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QWD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6QWD FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=6qwd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qwd OCA], [https://pdbe.org/6qwd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6qwd RCSB], [https://www.ebi.ac.uk/pdbsum/6qwd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6qwd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BLKPC_KLEPN BLKPC_KLEPN] Hydrolyzes carbapenems, penicillins, cephalosporins and monobactams with varying efficiency.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
beta-Lactamase production is the major beta-lactam resistance mechanism in Gram-negative bacteria. beta-Lactamase inhibitors (BLIs) efficacious against serine beta-lactamase (SBL) producers, especially strains carrying the widely disseminated class A enzymes, are required. Relebactam, a diazabicyclooctane (DBO) BLI is in phase-3 clinical trials in combination with imipenem, for treatment of infections by multi-drug resistant Enterobacteriaceae. We show that relebactam inhibits five clinically-important class A SBLs (despite their differing spectra of activity), representing both chromosomal and plasmid-borne enzymes, i.e. the extended spectrum beta-lactamases L2 (inhibition constant 3 muM) and CTX-M-15 (21 muM); and the carbapenemases, KPC-2, -3 and -4 (1 - 5 muM). Against purified class A SBLs, relebactam is an inferior inhibitor compared to the clinically approved DBO avibactam, (9 to 120-fold differences in IC50). Minimum inhibitory concentration assays indicate relebactam potentiates beta-lactam (imipenem) activity against KPC-producing Klebsiella pneumoniae with similar potency to avibactam (with ceftazidime). Relebactam is less effective than avibactam in combination with aztreonam against Stenotrophomonas maltophilia K279a. X-ray crystal structures of relebactam bound to CTX-M-15, L2, KPC-2, KPC-3 and KPC-4 reveal its C2 linked piperidine ring can sterically clash with Asn104 (CTX-M-15) or His/Trp105 (L2 and KPCs), rationalizing its poorer inhibition activity compared to avibactam, which has a smaller C2 carboxyamide group. Mass spectrometry and crystallographic data show slow, pH-dependent relebactam desulfation by KPC-2, -3 and -4. This comprehensive comparison of relebactam binding across five clinically-important class A SBLs will inform the design of future DBOs with the aim of improving clinical efficacy of BLI:beta-lactam combinations.

Molecular Basis of Class A beta-lactamase Inhibition by Relebactam.,Tooke CL, Hinchliffe P, Lang PA, Mulholland AJ, Brem J, Schofield CJ, Spencer J Antimicrob Agents Chemother. 2019 Aug 5. pii: AAC.00564-19. doi:, 10.1128/AAC.00564-19. PMID:31383664<ref>PMID:31383664</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6qwd" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Klebsiella pneumoniae]]
[[Category: Large Structures]]
[[Category: Hinchliffe P]]
[[Category: Spencer J]]
[[Category: Tooke CL]]