View source for 6twt


==Crystal structure of N-terminally truncated NDM-1 metallo-beta-lactamase==
<StructureSection load='6twt' size='340' side='right'caption='[[6twt]], [[Resolution|resolution]] 0.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6twt]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Klebsiella_pneumoniae Klebsiella pneumoniae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6TWT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6TWT 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]] 0.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=6twt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6twt OCA], [https://pdbe.org/6twt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6twt RCSB], [https://www.ebi.ac.uk/pdbsum/6twt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6twt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BLAN1_KLEPN BLAN1_KLEPN] Confers resistance to many beta-lactam antibiotics, including some carbapenems. Does not confer resistance to the polymixin colistin or the fluoroquinolone ciprofloxacin.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Two accessory loop regions that are present in numerous variants of New Delhi metallo-beta-lactamases (NDM) are important for the enzymatic activity. The first one is a flexible loop L3 that is located near the active site and is thought to play an important role in the catalytic process. The second region, Omega loop is located close to a structural element that coordinates two essential zinc ions. Both loops are not involved in any specific interactions with a substrate. Herein, we investigated how the length and hydrophobicity of loop L3 influence the enzymatic activity of NDMs, by analyzing mutants of NDM-1 with various deletions/point mutations within the L3 loop. We also investigated NDM variants with sequence variations/artificial deletions within the Omega loop. For all these variants we determined kinetic parameters for the hydrolysis of ampicillin, imipenem, and a chromogenic cephalosporin (CENTA). None of the mutations in the L3 loop completely abolished the enzymatic activity of NDM-1. Our results suggest that various elements of the loop play different roles in the hydrolysis of different substrates and the flexibility of the loop seems necessary to fulfill the requirements imposed by various substrates. Deletions within the Omega loop usually enhanced the enzymatic activity, particularly for the hydrolysis of ampicillin and imipenem. However, the exact role of the Omega loop in the catalytic reaction remains unclear. In our kinetic tests, the NDM enzymes were inhibited in the beta-lactamase reaction by the CENTA substrate. We also present the X-ray crystal structures of the NDM-1, NDM-9 and NDM-12 proteins.

Flexible loops of New Delhi metallo-beta-lactamase modulate its activity towards different substrates.,Raczynska JE, Imiolczyk B, Komorowska M, Sliwiak J, Czyrko-Horczak J, Brzezinski K, Jaskolski M Int J Biol Macromol. 2020 Apr 28;158:104-115. doi:, 10.1016/j.ijbiomac.2020.04.219. PMID:32353499<ref>PMID:32353499</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6twt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Klebsiella pneumoniae]]
[[Category: Large Structures]]
[[Category: Brzezinski K]]
[[Category: Czyrko-Horczak J]]
[[Category: Imiolczyk B]]
[[Category: Jaskolski M]]