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== | ==AmpC beta-lactamase N289A mutant in complex with a boronic acid deacylation transition state analog compound SM3== | ||
<StructureSection load='2ffy' size='340' side='right'caption='[[2ffy]], [[Resolution|resolution]] 1.07Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2ffy]] is a 2 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=2FFY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2FFY 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]] 1.07Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=SM3:(1R)-1-(2-THIENYLACETYLAMINO)-1-PHENYLMETHYLBORONIC+ACID'>SM3</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=2ffy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ffy OCA], [https://pdbe.org/2ffy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ffy RCSB], [https://www.ebi.ac.uk/pdbsum/2ffy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ffy ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/AMPC_ECOLI AMPC_ECOLI] This protein is a serine beta-lactamase with a substrate specificity for cephalosporins. | |||
== 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/ff/2ffy_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=2ffy ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Beta-lactamases confer bacterial resistance to beta-lactam antibiotics, such as penicillins. The characteristic class C beta-lactamase AmpC catalyzes the reaction with several key residues including Ser64, Tyr150, and Lys67. Here, we describe a 1.07 A X-ray crystallographic structure of AmpC beta-lactamase in complex with a boronic acid deacylation transition-state analogue. The high quality of the electron density map allows the determination of many proton positions. The proton on the Tyr150 hydroxyl group is clearly visible and is donated to the boronic oxygen mimicking the deacylation water. Meanwhile, Lys67 hydrogen bonds with Ser64Ogamma, Asn152Odelta1, and the backbone oxygen of Ala220. This suggests that this residue is positively charged and has relinquished the hydrogen bond with Tyr150 observed in acyl-enzyme complex structures. Together with previous biochemical and NMR studies, these observations indicate that Tyr150 is protonated throughout the reaction coordinate, disfavoring mechanisms that involve a stable tyrosinate as the general base for deacylation. Rather, the hydroxyl of Tyr150 appears to be well positioned to electrostatically stabilize the negative charge buildup in the tetrahedral high-energy intermediate. This structure, in itself, appears consistent with a mechanism involving either Tyr150 acting as a transient catalytic base in conjunction with a neutral Lys67 or the lactam nitrogen as the general base. Whereas mutagenesis studies suggest that Lys67 may be replaced by an arginine, disfavoring the conjugate base mechanism, distinguishing between these two hypotheses may ultimately depend on direct determination of the pK(a) of Lys67 along the reaction coordinate. | Beta-lactamases confer bacterial resistance to beta-lactam antibiotics, such as penicillins. The characteristic class C beta-lactamase AmpC catalyzes the reaction with several key residues including Ser64, Tyr150, and Lys67. Here, we describe a 1.07 A X-ray crystallographic structure of AmpC beta-lactamase in complex with a boronic acid deacylation transition-state analogue. The high quality of the electron density map allows the determination of many proton positions. The proton on the Tyr150 hydroxyl group is clearly visible and is donated to the boronic oxygen mimicking the deacylation water. Meanwhile, Lys67 hydrogen bonds with Ser64Ogamma, Asn152Odelta1, and the backbone oxygen of Ala220. This suggests that this residue is positively charged and has relinquished the hydrogen bond with Tyr150 observed in acyl-enzyme complex structures. Together with previous biochemical and NMR studies, these observations indicate that Tyr150 is protonated throughout the reaction coordinate, disfavoring mechanisms that involve a stable tyrosinate as the general base for deacylation. Rather, the hydroxyl of Tyr150 appears to be well positioned to electrostatically stabilize the negative charge buildup in the tetrahedral high-energy intermediate. This structure, in itself, appears consistent with a mechanism involving either Tyr150 acting as a transient catalytic base in conjunction with a neutral Lys67 or the lactam nitrogen as the general base. Whereas mutagenesis studies suggest that Lys67 may be replaced by an arginine, disfavoring the conjugate base mechanism, distinguishing between these two hypotheses may ultimately depend on direct determination of the pK(a) of Lys67 along the reaction coordinate. | ||
The deacylation mechanism of AmpC beta-lactamase at ultrahigh resolution.,Chen Y, Minasov G, Roth TA, Prati F, Shoichet BK J Am Chem Soc. 2006 Mar 8;128(9):2970-6. PMID:16506777<ref>PMID:16506777</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[ | <div class="pdbe-citations 2ffy" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Chen | [[Category: Chen Y]] | ||
[[Category: Minasov | [[Category: Minasov G]] | ||
[[Category: Prati | [[Category: Prati F]] | ||
[[Category: Roth | [[Category: Roth TA]] | ||
[[Category: Shoichet | [[Category: Shoichet BK]] | ||
Latest revision as of 03:55, 21 November 2024
AmpC beta-lactamase N289A mutant in complex with a boronic acid deacylation transition state analog compound SM3AmpC beta-lactamase N289A mutant in complex with a boronic acid deacylation transition state analog compound SM3
Structural highlights
FunctionAMPC_ECOLI This protein is a serine beta-lactamase with a substrate specificity for cephalosporins. 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 PubMedBeta-lactamases confer bacterial resistance to beta-lactam antibiotics, such as penicillins. The characteristic class C beta-lactamase AmpC catalyzes the reaction with several key residues including Ser64, Tyr150, and Lys67. Here, we describe a 1.07 A X-ray crystallographic structure of AmpC beta-lactamase in complex with a boronic acid deacylation transition-state analogue. The high quality of the electron density map allows the determination of many proton positions. The proton on the Tyr150 hydroxyl group is clearly visible and is donated to the boronic oxygen mimicking the deacylation water. Meanwhile, Lys67 hydrogen bonds with Ser64Ogamma, Asn152Odelta1, and the backbone oxygen of Ala220. This suggests that this residue is positively charged and has relinquished the hydrogen bond with Tyr150 observed in acyl-enzyme complex structures. Together with previous biochemical and NMR studies, these observations indicate that Tyr150 is protonated throughout the reaction coordinate, disfavoring mechanisms that involve a stable tyrosinate as the general base for deacylation. Rather, the hydroxyl of Tyr150 appears to be well positioned to electrostatically stabilize the negative charge buildup in the tetrahedral high-energy intermediate. This structure, in itself, appears consistent with a mechanism involving either Tyr150 acting as a transient catalytic base in conjunction with a neutral Lys67 or the lactam nitrogen as the general base. Whereas mutagenesis studies suggest that Lys67 may be replaced by an arginine, disfavoring the conjugate base mechanism, distinguishing between these two hypotheses may ultimately depend on direct determination of the pK(a) of Lys67 along the reaction coordinate. The deacylation mechanism of AmpC beta-lactamase at ultrahigh resolution.,Chen Y, Minasov G, Roth TA, Prati F, Shoichet BK J Am Chem Soc. 2006 Mar 8;128(9):2970-6. PMID:16506777[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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