1blc: Difference between revisions
No edit summary |
No edit summary |
||
| (16 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
== | ==INHIBITION OF BETA-LACTAMASE BY CLAVULANATE: TRAPPED INTERMEDIATES IN CRYOCRYSTALLOGRAPHIC STUDIES== | ||
<StructureSection load='1blc' size='340' side='right'caption='[[1blc]], [[Resolution|resolution]] 2.20Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1blc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BLC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BLC 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]] 2.2Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CEM:N-(1-CARBOXY-2-HYDROXY-4-OXO-BUTYL)-N-(3-OXO-CISPROPENYL)AMINE'>CEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=TEM:N-(2-HYDROXY-4-OXO-BUTYL)-N-(3-OXO-TRANSPROPENYL)AMINE'>TEM</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=1blc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1blc OCA], [https://pdbe.org/1blc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1blc RCSB], [https://www.ebi.ac.uk/pdbsum/1blc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1blc ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/BLAC_STAAU BLAC_STAAU] | |||
== 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/bl/1blc_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=1blc ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Crystallographic studies of the complex between beta-lactamase and clavulanate reveal a structure of two acyl-enzymes with covalent bonds at the active site Ser70, representing two different stages of inhibitor degradation alternately occupying the active site. Models that are consistent with biochemical data are derived from the electron density map and refined at 2.2 A resolution: cis enamine, in which the carboxylate group of the clavulanate molecule makes a salt bridge with Lys234 of beta-lactamase; decarboxylated trans enamine, which is oriented away from Lys234. For both acyl-enzymes, the carbonyl oxygen atom of the ester group occupies the oxyanion hole in a manner similar to that found in inhibitor binding to serine proteases. Whereas the oxygen atom in the trans product is optimally positioned in the oxyanion hole, that of the cis product clashes with the main-chain nitrogen atom of Ser70 and the beta-carbon atom of the adjacent Ala69. In contrast to cis to trans isomerization in solution that relieves the steric strain inherent in a cis double bond, at the enzyme-inhibitor interface two additional factors play an important role. The salt bridge enhances the stability of the cis product, while the steric strain introduced by the short contacts with the protein reduces its stability. | Crystallographic studies of the complex between beta-lactamase and clavulanate reveal a structure of two acyl-enzymes with covalent bonds at the active site Ser70, representing two different stages of inhibitor degradation alternately occupying the active site. Models that are consistent with biochemical data are derived from the electron density map and refined at 2.2 A resolution: cis enamine, in which the carboxylate group of the clavulanate molecule makes a salt bridge with Lys234 of beta-lactamase; decarboxylated trans enamine, which is oriented away from Lys234. For both acyl-enzymes, the carbonyl oxygen atom of the ester group occupies the oxyanion hole in a manner similar to that found in inhibitor binding to serine proteases. Whereas the oxygen atom in the trans product is optimally positioned in the oxyanion hole, that of the cis product clashes with the main-chain nitrogen atom of Ser70 and the beta-carbon atom of the adjacent Ala69. In contrast to cis to trans isomerization in solution that relieves the steric strain inherent in a cis double bond, at the enzyme-inhibitor interface two additional factors play an important role. The salt bridge enhances the stability of the cis product, while the steric strain introduced by the short contacts with the protein reduces its stability. | ||
Inhibition of beta-lactamase by clavulanate. Trapped intermediates in cryocrystallographic studies.,Chen CC, Herzberg O J Mol Biol. 1992 Apr 20;224(4):1103-13. PMID:1569569<ref>PMID:1569569</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[ | <div class="pdbe-citations 1blc" style="background-color:#fffaf0;"></div> | ||
[[Category: | |||
==See Also== | |||
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
[[Category: Chen | [[Category: Chen CCH]] | ||
[[Category: Herzberg | [[Category: Herzberg O]] | ||