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7k2w

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Current revision

Crystal structure of CTX-M-14 E166A/K234R Beta-lactamase in complex with hydrolyzed cefotaxime

Structural highlights

7k2w is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.4Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q9L5C7_ECOLX

Publication Abstract from PubMed

Lys(234) is one of the residues present in class A beta-lactamases that is under selective pressure due to antibiotic use. Located adjacent to proton shuttle residue Ser(130), it is suggested to play a role in proton transfer during catalysis of the antibiotics. The mechanism underpinning how substitutions in this position modulate inhibitor efficiency and substrate specificity leading to drug resistance is unclear. The K234R substitution identified in several inhibitor-resistant beta-lactamase variants is associated with decreased potency of the inhibitor clavulanic acid, which is used in combination with amoxicillin to overcome beta-lactamase-mediated antibiotic resistance. Here we show that for CTX-M-14 beta-lactamase, whereas Lys(234) is required for hydrolysis of cephalosporins such as cefotaxime, either lysine or arginine is sufficient for hydrolysis of ampicillin. Further, by determining the acylation and deacylation rates for cefotaxime hydrolysis, we show that both rates are fast, and neither is rate-limiting. The K234R substitution causes a 1500-fold decrease in the cefotaxime acylation rate but a 5-fold increase in k cat for ampicillin, suggesting that the K234R enzyme is a good penicillinase but a poor cephalosporinase due to slow acylation. Structural results suggest that the slow acylation by the K234R enzyme is due to a conformational change in Ser(130), and this change also leads to decreased inhibition potency of clavulanic acid. Because other inhibitor resistance mutations also act through changes at Ser(130) and such changes drastically reduce cephalosporin but not penicillin hydrolysis, we suggest that clavulanic acid paired with an oxyimino-cephalosporin rather than penicillin would impede the evolution of resistance.

A drug-resistant beta-lactamase variant changes the conformation of its active-site proton shuttle to alter substrate specificity and inhibitor potency.,Soeung V, Lu S, Hu L, Judge A, Sankaran B, Prasad BVV, Palzkill T J Biol Chem. 2020 Dec 25;295(52):18239-18255. doi: 10.1074/jbc.RA120.016103. Epub, 2020 Oct 26. PMID:33109613^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Soeung V, Lu S, Hu L, Judge A, Sankaran B, Prasad BVV, Palzkill T. A drug-resistant beta-lactamase variant changes the conformation of its active-site proton shuttle to alter substrate specificity and inhibitor potency. J Biol Chem. 2020 Dec 25;295(52):18239-18255. doi: 10.1074/jbc.RA120.016103. Epub, 2020 Oct 26. PMID:33109613 doi:http://dx.doi.org/10.1074/jbc.RA120.016103

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/7k2w"

@@ Line 3: / Line 3: @@
 <StructureSection load='7k2w' size='340' side='right'caption='[[7k2w]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[7k2w]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7K2W OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7K2W FirstGlance]. <br>
+<table><tr><td colspan='2'>[[7k2w]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7K2W OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7K2W FirstGlance]. <br>
-</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>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.4&#8491;</td></tr>
-<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=UNK:UNKNOWN'>UNK</scene></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='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">blaCTX-M ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr>
-<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'>[https://proteopedia.org/fgij/fg.htm?mol=7k2w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7k2w OCA], [https://pdbe.org/7k2w PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7k2w RCSB], [https://www.ebi.ac.uk/pdbsum/7k2w PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7k2w ProSAT]</span></td></tr>
 </table>
+== Function ==
+[https://www.uniprot.org/uniprot/Q9L5C7_ECOLX Q9L5C7_ECOLX]
 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==
@@ Line 26: / Line 26: @@
 __TOC__
 </StructureSection>
-[[Category: Bacillus coli migula 1895]]
+[[Category: Escherichia coli]]
-[[Category: Beta-lactamase]]
 [[Category: Large Structures]]
-[[Category: Hu, L]]
+[[Category: Hu L]]
-[[Category: Lu, S]]
+[[Category: Lu S]]
-[[Category: Palzkill, T]]
+[[Category: Palzkill T]]
-[[Category: Prasad, B V.V]]
+[[Category: Prasad BVV]]
-[[Category: Sankaran, B]]
+[[Category: Sankaran B]]
-[[Category: Soeung, V]]
+[[Category: Soeung V]]
-[[Category: Acyl-enzyme intermediate]]
-[[Category: Antibiotic resistance]]
-[[Category: Hydrolase]]

7k2w

From Proteopedia

Current revision

Crystal structure of CTX-M-14 E166A/K234R Beta-lactamase in complex with hydrolyzed cefotaxime

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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