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4k0w
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4k0w]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Acinetobacter_baumannii Acinetobacter baumannii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4K0W OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4K0W FirstGlance]. <br> | <table><tr><td colspan='2'>[[4k0w]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Acinetobacter_baumannii Acinetobacter baumannii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4K0W OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4K0W FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BCT:BICARBONATE+ION'>BCT</scene>, <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.2Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BCT:BICARBONATE+ION'>BCT</scene>, <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=4k0w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4k0w OCA], [https://pdbe.org/4k0w PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4k0w RCSB], [https://www.ebi.ac.uk/pdbsum/4k0w PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4k0w ProSAT]</span></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=4k0w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4k0w OCA], [https://pdbe.org/4k0w PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4k0w RCSB], [https://www.ebi.ac.uk/pdbsum/4k0w PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4k0w ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/B6E129_ACIBA B6E129_ACIBA] | [https://www.uniprot.org/uniprot/B6E129_ACIBA B6E129_ACIBA] | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | Class D beta-lactamases that hydrolyze carbapenems such as imipenem and doripenem are a recognized danger to the efficacy of these "last resort" beta-lactam antibiotics. Like all known class D carbapenemases, OXA-23 cannot hydrolyze the expanded-spectrum cephalosporin, ceftazidime. OXA-146 is an OXA-23 subfamily clinical variant that differs from the parent enzyme by a single alanine (A220) inserted in the loop connecting beta-strands beta5 and beta6. We discovered that this insertion enables OXA-146 to bind and hydrolyze ceftazidime with efficiency comparable to other extended-spectrum class D beta-lactamases. OXA-146 also binds and hydrolyzes aztreonam, cefotaxime, ceftriaxone and ampicillin with higher efficiency than OXA-23, and preserves activity against doripenem. In this study, we report the X-ray crystal structures of both the OXA-23 and OXA-146 enzymes at 1.6 A and 1.2 A resolution. A comparison of the two structures shows that the extra alanine moves a methionine (M221) out of its normal position where it forms a bridge over the top of the active site. This single amino acid insertion also lengthens the beta5-beta6 loop, moving the entire backbone of this region further away from the active site. A model of ceftazidime bound in the active site reveals that these two structural alterations are both likely to relieve steric clashes between the bulky R1 side-chain of ceftazidime and OXA-23. With activity against all four classes of beta-lactam antibiotics, OXA-146 represents an alarming new threat to the treatment of infections caused by Acinetobacter spp. | ||
| - | |||
| - | STRUCTURES OF THE CLASS D CARBAPENEMASES OXA-23 AND OXA-146: MECHANISTIC BASIS OF ACTIVITY AGAINST CARBAPENEMS, EXTENDED-SPECTRUM CEPHALOSPORINS AND AZTREONAM.,Kaitany KC, Klinger NV, June CM, Ramey ME, Bonomo RA, Powers RA, Leonard DA Antimicrob Agents Chemother. 2013 Jul 22. PMID:23877677<ref>PMID:23877677</ref> | ||
| - | |||
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
| - | <div class="pdbe-citations 4k0w" style="background-color:#fffaf0;"></div> | ||
==See Also== | ==See Also== | ||
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] | *[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]] | ||
| - | == References == | ||
| - | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Current revision
X-ray crystal structure of OXA-23 A220 duplication clinical variant
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