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| - | [[Image:1ck3.jpg|left|200px]] | |
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| - | <!--
| + | ==N276D MUTANT OF ESCHERICHIA COLI TEM-1 BETA-LACTAMASE== |
| - | The line below this paragraph, containing "STRUCTURE_1ck3", creates the "Structure Box" on the page.
| + | <StructureSection load='1ck3' size='340' side='right'caption='[[1ck3]], [[Resolution|resolution]] 2.28Å' scene=''> |
| - | You may change the PDB parameter (which sets the PDB file loaded into the applet) | + | == Structural highlights == |
| - | or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
| + | <table><tr><td colspan='2'>[[1ck3]] 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=1CK3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CK3 FirstGlance]. <br> |
| - | or leave the SCENE parameter empty for the default display.
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.28Å</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=1ck3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ck3 OCA], [https://pdbe.org/1ck3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ck3 RCSB], [https://www.ebi.ac.uk/pdbsum/1ck3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ck3 ProSAT]</span></td></tr> |
| - | {{STRUCTURE_1ck3| PDB=1ck3 | SCENE= }}
| + | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/BLAT_ECOLX BLAT_ECOLX] TEM-type are the most prevalent beta-lactamases in enterobacteria; they hydrolyze the beta-lactam bond in susceptible beta-lactam antibiotics, thus conferring resistance to penicillins and cephalosporins. TEM-3 and TEM-4 are capable of hydrolyzing cefotaxime and ceftazidime. TEM-5 is capable of hydrolyzing ceftazidime. TEM-6 is capable of hydrolyzing ceftazidime and aztreonam. TEM-8/CAZ-2, TEM-16/CAZ-7 and TEM-24/CAZ-6 are markedly active against ceftazidime. IRT-4 shows resistance to beta-lactamase inhibitors. |
| | + | == Evolutionary Conservation == |
| | + | [[Image:Consurf_key_small.gif|200px|right]] |
| | + | Check<jmol> |
| | + | <jmolCheckbox> |
| | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ck/1ck3_consurf.spt"</scriptWhenChecked> |
| | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> |
| | + | <text>to colour the structure by Evolutionary Conservation</text> |
| | + | </jmolCheckbox> |
| | + | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1ck3 ConSurf]. |
| | + | <div style="clear:both"></div> |
| | + | <div style="background-color:#fffaf0;"> |
| | + | == Publication Abstract from PubMed == |
| | + | The clinical use of beta-lactam antibiotics combined with beta-lactamase inactivators, such as clavulanate, has resulted in selection of beta-lactamases that are insensitive to inactivation by these molecules. Therefore, therapeutic combinations of an enzyme inactivator and a penicillin are harmless for bacteria harboring such an enzyme. The TEM beta-lactamase variants are the most frequently encountered enzymes of this type, and presently, 20 variants are designated as inhibitor-resistant TEM ("IRT") enzymes. Three mutations appear to account for the phenotype of the majority of IRT enzymes, one of them being the Asn276Asp substitution. In this study, we have characterized the kinetic properties of the inhibition process of the wild-type TEM-1 beta-lactamase and of its Asn276Asp variant with the three clinically used inactivators, clavulanic acid (clavulanate), sulbactam, and tazobactam, and we report the X-ray structure for the mutant variant at 2.3 A resolution. The changes in kinetic parameters for the interactions of the inhibitors with the wild-type and the mutant enzymes were more pronounced for clavulanate, and relatively inconsequential for sulbactam and tazobactam. The structure of the Asn276Asp mutant enzyme revealed a significant movement of Asp276 and the formation of a salt bridge of its side chain with the guanidinium group of Arg244, the counterion of the inhibitor carboxylate. A water molecule critical for the inactivation chemistry by clavulanate, which is observed in the wild-type enzyme structure, is not present in the crystal structure of the mutant variant. Such structural changes favor the turnover process over the inactivation chemistry for clavulanate, with profound phenotypic consequences. The report herein represents the best studied example of inhibitor-resistant beta-lactamases. |
| | | | |
| - | '''N276D MUTANT OF ESCHERICHIA COLI TEM-1 BETA-LACTAMASE'''
| + | X-ray structure of the Asn276Asp variant of the Escherichia coli TEM-1 beta-lactamase: direct observation of electrostatic modulation in resistance to inactivation by clavulanic acid.,Swaren P, Golemi D, Cabantous S, Bulychev A, Maveyraud L, Mobashery S, Samama JP Biochemistry. 1999 Jul 27;38(30):9570-6. PMID:10423234<ref>PMID:10423234</ref> |
| - | | + | |
| - | | + | |
| - | ==Overview==
| + | |
| - | The clinical use of beta-lactam antibiotics combined with beta-lactamase inactivators, such as clavulanate, has resulted in selection of beta-lactamases that are insensitive to inactivation by these molecules. Therefore, therapeutic combinations of an enzyme inactivator and a penicillin are harmless for bacteria harboring such an enzyme. The TEM beta-lactamase variants are the most frequently encountered enzymes of this type, and presently, 20 variants are designated as inhibitor-resistant TEM ("IRT") enzymes. Three mutations appear to account for the phenotype of the majority of IRT enzymes, one of them being the Asn276Asp substitution. In this study, we have characterized the kinetic properties of the inhibition process of the wild-type TEM-1 beta-lactamase and of its Asn276Asp variant with the three clinically used inactivators, clavulanic acid (clavulanate), sulbactam, and tazobactam, and we report the X-ray structure for the mutant variant at 2.3 A resolution. The changes in kinetic parameters for the interactions of the inhibitors with the wild-type and the mutant enzymes were more pronounced for clavulanate, and relatively inconsequential for sulbactam and tazobactam. The structure of the Asn276Asp mutant enzyme revealed a significant movement of Asp276 and the formation of a salt bridge of its side chain with the guanidinium group of Arg244, the counterion of the inhibitor carboxylate. A water molecule critical for the inactivation chemistry by clavulanate, which is observed in the wild-type enzyme structure, is not present in the crystal structure of the mutant variant. Such structural changes favor the turnover process over the inactivation chemistry for clavulanate, with profound phenotypic consequences. The report herein represents the best studied example of inhibitor-resistant beta-lactamases.
| + | |
| | | | |
| - | ==About this Structure==
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| - | 1CK3 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CK3 OCA].
| + | </div> |
| | + | <div class="pdbe-citations 1ck3" style="background-color:#fffaf0;"></div> |
| | | | |
| - | ==Reference== | + | ==See Also== |
| - | X-ray structure of the Asn276Asp variant of the Escherichia coli TEM-1 beta-lactamase: direct observation of electrostatic modulation in resistance to inactivation by clavulanic acid., Swaren P, Golemi D, Cabantous S, Bulychev A, Maveyraud L, Mobashery S, Samama JP, Biochemistry. 1999 Jul 27;38(30):9570-6. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10423234 10423234]
| + | *[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] |
| - | [[Category: Beta-lactamase]] | + | == References == |
| | + | <references/> |
| | + | __TOC__ |
| | + | </StructureSection> |
| | [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| - | [[Category: Single protein]] | + | [[Category: Large Structures]] |
| - | [[Category: Maveyraud, L.]] | + | [[Category: Maveyraud L]] |
| - | [[Category: Samama, J P.]] | + | [[Category: Samama JP]] |
| - | [[Category: Swaren, P.]] | + | [[Category: Swaren P]] |
| - | [[Category: Beta-lactamase]]
| + | |
| - | [[Category: Clavulanate-resistant]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 12:49:09 2008''
| + | |
| Structural highlights
Function
BLAT_ECOLX TEM-type are the most prevalent beta-lactamases in enterobacteria; they hydrolyze the beta-lactam bond in susceptible beta-lactam antibiotics, thus conferring resistance to penicillins and cephalosporins. TEM-3 and TEM-4 are capable of hydrolyzing cefotaxime and ceftazidime. TEM-5 is capable of hydrolyzing ceftazidime. TEM-6 is capable of hydrolyzing ceftazidime and aztreonam. TEM-8/CAZ-2, TEM-16/CAZ-7 and TEM-24/CAZ-6 are markedly active against ceftazidime. IRT-4 shows resistance to beta-lactamase inhibitors.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The clinical use of beta-lactam antibiotics combined with beta-lactamase inactivators, such as clavulanate, has resulted in selection of beta-lactamases that are insensitive to inactivation by these molecules. Therefore, therapeutic combinations of an enzyme inactivator and a penicillin are harmless for bacteria harboring such an enzyme. The TEM beta-lactamase variants are the most frequently encountered enzymes of this type, and presently, 20 variants are designated as inhibitor-resistant TEM ("IRT") enzymes. Three mutations appear to account for the phenotype of the majority of IRT enzymes, one of them being the Asn276Asp substitution. In this study, we have characterized the kinetic properties of the inhibition process of the wild-type TEM-1 beta-lactamase and of its Asn276Asp variant with the three clinically used inactivators, clavulanic acid (clavulanate), sulbactam, and tazobactam, and we report the X-ray structure for the mutant variant at 2.3 A resolution. The changes in kinetic parameters for the interactions of the inhibitors with the wild-type and the mutant enzymes were more pronounced for clavulanate, and relatively inconsequential for sulbactam and tazobactam. The structure of the Asn276Asp mutant enzyme revealed a significant movement of Asp276 and the formation of a salt bridge of its side chain with the guanidinium group of Arg244, the counterion of the inhibitor carboxylate. A water molecule critical for the inactivation chemistry by clavulanate, which is observed in the wild-type enzyme structure, is not present in the crystal structure of the mutant variant. Such structural changes favor the turnover process over the inactivation chemistry for clavulanate, with profound phenotypic consequences. The report herein represents the best studied example of inhibitor-resistant beta-lactamases.
X-ray structure of the Asn276Asp variant of the Escherichia coli TEM-1 beta-lactamase: direct observation of electrostatic modulation in resistance to inactivation by clavulanic acid.,Swaren P, Golemi D, Cabantous S, Bulychev A, Maveyraud L, Mobashery S, Samama JP Biochemistry. 1999 Jul 27;38(30):9570-6. PMID:10423234[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Swaren P, Golemi D, Cabantous S, Bulychev A, Maveyraud L, Mobashery S, Samama JP. X-ray structure of the Asn276Asp variant of the Escherichia coli TEM-1 beta-lactamase: direct observation of electrostatic modulation in resistance to inactivation by clavulanic acid. Biochemistry. 1999 Jul 27;38(30):9570-6. PMID:10423234 doi:10.1021/bi990758z
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