1xpb: Difference between revisions
From Proteopedia
Jump to navigationJump to search
New page: left|200px<br /> <applet load="1xpb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xpb, resolution 1.90Å" /> '''STRUCTURE OF BETA-L... |
No edit summary |
||
| (23 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
== | ==STRUCTURE OF BETA-LACTAMASE TEM1== | ||
beta-Lactamases are bacterial enzymes which catalyse the hydrolysis of the | <StructureSection load='1xpb' size='340' side='right'caption='[[1xpb]], [[Resolution|resolution]] 1.90Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1xpb]] 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=1XPB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XPB 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]] 1.9Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1xpb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xpb OCA], [https://pdbe.org/1xpb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xpb RCSB], [https://www.ebi.ac.uk/pdbsum/1xpb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xpb ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/BLAT_ECOLX BLAT_ECOLX] TEM-type are the most prevalent beta-lactamases in enterobacteria; they hydrolyze the beta-lactam bond in susceptible beta-lactam antibiotics, thus conferring resistance to penicillins and cephalosporins. TEM-3 and TEM-4 are capable of hydrolyzing cefotaxime and ceftazidime. TEM-5 is capable of hydrolyzing ceftazidime. TEM-6 is capable of hydrolyzing ceftazidime and aztreonam. TEM-8/CAZ-2, TEM-16/CAZ-7 and TEM-24/CAZ-6 are markedly active against ceftazidime. IRT-4 shows resistance to beta-lactamase inhibitors. | |||
== 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/xp/1xpb_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=1xpb ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
beta-Lactamases are bacterial enzymes which catalyse the hydrolysis of the beta-lactam ring of penicillins, cephalosporins and related compounds, thus inactivating these antibiotics. The crystal structure of the TEM1 beta-lactamase has been determined at 1.9 A resolution by the molecular-replacement method, using the atomic coordinates of two homologous beta-lactamase refined structures which show about 36% strict identity in their amino-acid sequences and 1.96 A r.m.s. deviation between equivalent Calpha atoms. The TEM1 enzyme crystallizes in space group P2(1)2(1)2(1) and there is one molecule per asymmetric unit. The structure was refined by simulated annealing to an R-factor of 15.6% for 15 086 reflections with I >/= 2sigma(I) in the resolution range 5.0-1.9 A. The final crystallographic structure contains 263 amino-acid residues, one sulfate anion in the catalytic cleft and 135 water molecules per asymmetric unit. The folding is very similar to that of the other known class A beta-lactamases. It consists of two domains, the first is formed by a five-stranded beta-sheet covered by three alpha-helices on one face and one alpha-helix on the other, the second domain contains mainly alpha-helices. The catalytic cleft is located at the interface between the two domains. We also report the crystallographic study of the TEM S235A mutant. This mutation of an active-site residue specifically decreases the acylation rate of cephalosporins. This TEM S235A mutant crystallizes under the same conditions as the wild-type protein and its structure was refined at 2.0 A resolution with an R value of 17.6%. The major modification is the appearance of a water molecule near the mutated residue, which is incompatible with the OG 235 present in the wild-type enzyme, and causes very small perturbations in the interaction network in the active site. | |||
TEM1 beta-lactamase structure solved by molecular replacement and refined structure of the S235A mutant.,Fonze E, Charlier P, To'th Y, Vermeire M, Raquet X, Dubus A, Frere JM Acta Crystallogr D Biol Crystallogr. 1995 Sep 1;51(Pt 5):682-94. PMID:15299797<ref>PMID:15299797</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
<div class="pdbe-citations 1xpb" 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: Charlier | [[Category: Charlier P]] | ||
[[Category: Fonze | [[Category: Fonze E]] | ||
