View source for 5a90


==100K Neutron Ligand Free: Exploring the Mechanism of beta-Lactam Ring Protonation in the Class A beta-lactamase Acylation Mechanism Using Neutron and X-ray Crystallography==
<StructureSection load='5a90' size='340' side='right'caption='[[5a90]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5a90]] 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=5A90 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5A90 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Neutron Diffraction, [[Resolution|Resolution]] 1.7&#8491;</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=5a90 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5a90 OCA], [https://pdbe.org/5a90 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5a90 RCSB], [https://www.ebi.ac.uk/pdbsum/5a90 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5a90 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BLC97_ECOLX BLC97_ECOLX] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The catalytic mechanism of class A beta-lactamases is often debated due in part to the large number of amino acids that interact with bound beta-lactam substrates. The role and function of the conserved residue Lys 73 in the catalytic mechanism of class A type beta-lactamase enzymes is still not well understood after decades of scientific research. To better elucidate the functions of this vital residue, we used both neutron and high-resolution X-ray diffraction to examine both the structures of the ligand free protein and the acyl-enzyme complex of perdeuterated E166A Toho-1 beta-lactamase with the antibiotic cefotaxime. The E166A mutant lacks a critical glutamate residue that has a key role in the deacylation step of the catalytic mechanism, allowing the acyl-enzyme adduct to be captured for study. In our ligand free structures, Lys 73 is present in a single conformation, however in all of our acyl-enzyme structures, Lys 73 is present in two different conformations, in which one conformer is closer to Ser 70 while the other conformer is positioned closer to Ser 130, which supports the existence of a possible pathway by which proton transfer from Lys 73 to Ser 130 can occur. This and further clarifications of the role of Lys 73 in the acylation mechanism may facilitate the design of inhibitors that capitalize on the enzyme's native machinery.

Exploring the Mechanism of beta-Lactam Ring Protonation in the Class A beta-lactamase Acylation Mechanism Using Neutron and X-ray Crystallography.,Vandavasi VG, Weiss KL, Cooper JB, Erskine PT, Tomanicek SJ, Ostermann A, Schrader TE, Ginell SL, Coates L J Med Chem. 2015 Dec 2. PMID:26630115<ref>PMID:26630115</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5a90" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Coates L]]
[[Category: Cooper JB]]
[[Category: Erskine PT]]
[[Category: Ginell SL]]
[[Category: Ostermann A]]
[[Category: Schrader TE]]
[[Category: Tomanicek SJ]]
[[Category: Vandavasi VG]]
[[Category: Weiss KL]]