1li9: Difference between revisions
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[[Image: | ==Crystal structure of TEM-34 beta-Lactamase at 1.5 Angstrom== | ||
<StructureSection load='1li9' size='340' side='right' caption='[[1li9]], [[Resolution|resolution]] 1.52Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1li9]] is a 1 chain structure with 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=1LI9 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1LI9 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1lhy|1lhy]], [[1li0|1li0]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bla ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</td></tr> | |||
<tr><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><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1li9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1li9 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1li9 RCSB], [http://www.ebi.ac.uk/pdbsum/1li9 PDBsum]</span></td></tr> | |||
<table> | |||
== 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/li/1li9_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Widespread use of beta-lactam antibiotics has promoted the evolution of beta-lactamase mutant enzymes that can hydrolyze ever newer classes of these drugs. Among the most pernicious mutants are the inhibitor-resistant TEM beta-lactamases (IRTs), which elude mechanism-based inhibitors, such as clavulanate. Despite much research on these IRTs, little is known about the structural bases of their action. This has made it difficult to understand how many of the resistance substitutions act as they often occur far from Ser-130. Here, three IRT structures, TEM-30 (R244S), TEM-32 (M69I/M182T), and TEM-34 (M69V), are determined by x-ray crystallography at 2.00, 1.61, and 1.52 A, respectively. In TEM-30, the Arg-244 --> Ser substitution (7.8 A from Ser-130) displaces a conserved water molecule that usually interacts with the beta-lactam C3 carboxylate. In TEM-32, the substitution Met-69 --> Ile (10 A from Ser-130) appears to distort Ser-70, which in turn causes Ser-130 to adopt a new conformation, moving its O gamma further away, 2.3 A from where the inhibitor would bind. This substitution also destabilizes the enzyme by 1.3 kcal/mol. The Met-182 --> Thr substitution (20 A from Ser-130) has no effect on enzyme activity but rather restabilizes the enzyme by 2.9 kcal/mol. In TEM-34, the Met-69 --> Val substitution similarly leads to a conformational change in Ser-130, this time causing it to hydrogen bond with Lys-73 and Lys-234. This masks the lone pair electrons of Ser-130 O gamma, reducing its nucleophilicity for cross-linking. In these three structures, distant substitutions result in accommodations that converge on the same point of action, the local environment of Ser-130. | |||
The structural bases of antibiotic resistance in the clinically derived mutant beta-lactamases TEM-30, TEM-32, and TEM-34.,Wang X, Minasov G, Shoichet BK J Biol Chem. 2002 Aug 30;277(35):32149-56. Epub 2002 Jun 10. PMID:12058046<ref>PMID:12058046</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Beta-lactamase|Beta-lactamase]] | *[[Beta-lactamase|Beta-lactamase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Beta-lactamase]] | [[Category: Beta-lactamase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
Revision as of 17:15, 28 September 2014
Crystal structure of TEM-34 beta-Lactamase at 1.5 AngstromCrystal structure of TEM-34 beta-Lactamase at 1.5 Angstrom
Structural highlights
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 PubMedWidespread use of beta-lactam antibiotics has promoted the evolution of beta-lactamase mutant enzymes that can hydrolyze ever newer classes of these drugs. Among the most pernicious mutants are the inhibitor-resistant TEM beta-lactamases (IRTs), which elude mechanism-based inhibitors, such as clavulanate. Despite much research on these IRTs, little is known about the structural bases of their action. This has made it difficult to understand how many of the resistance substitutions act as they often occur far from Ser-130. Here, three IRT structures, TEM-30 (R244S), TEM-32 (M69I/M182T), and TEM-34 (M69V), are determined by x-ray crystallography at 2.00, 1.61, and 1.52 A, respectively. In TEM-30, the Arg-244 --> Ser substitution (7.8 A from Ser-130) displaces a conserved water molecule that usually interacts with the beta-lactam C3 carboxylate. In TEM-32, the substitution Met-69 --> Ile (10 A from Ser-130) appears to distort Ser-70, which in turn causes Ser-130 to adopt a new conformation, moving its O gamma further away, 2.3 A from where the inhibitor would bind. This substitution also destabilizes the enzyme by 1.3 kcal/mol. The Met-182 --> Thr substitution (20 A from Ser-130) has no effect on enzyme activity but rather restabilizes the enzyme by 2.9 kcal/mol. In TEM-34, the Met-69 --> Val substitution similarly leads to a conformational change in Ser-130, this time causing it to hydrogen bond with Lys-73 and Lys-234. This masks the lone pair electrons of Ser-130 O gamma, reducing its nucleophilicity for cross-linking. In these three structures, distant substitutions result in accommodations that converge on the same point of action, the local environment of Ser-130. The structural bases of antibiotic resistance in the clinically derived mutant beta-lactamases TEM-30, TEM-32, and TEM-34.,Wang X, Minasov G, Shoichet BK J Biol Chem. 2002 Aug 30;277(35):32149-56. Epub 2002 Jun 10. PMID:12058046[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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