View source for 1pyy


==Double mutant PBP2x T338A/M339F from Streptococcus pneumoniae strain R6 at 2.4 A resolution==
<StructureSection load='1pyy' size='340' side='right'caption='[[1pyy]], [[Resolution|resolution]] 2.42&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1pyy]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptococcus_pneumoniae_R6 Streptococcus pneumoniae R6]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PYY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PYY 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]] 2.42&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=PRD_900045:octanoyl-sucrose,+esterificated+at+fructose+C6'>PRD_900045</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=TRV:6-O-octanoyl-beta-D-fructofuranose'>TRV</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=1pyy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pyy OCA], [https://pdbe.org/1pyy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pyy RCSB], [https://www.ebi.ac.uk/pdbsum/1pyy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pyy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PBPX_STRR6 PBPX_STRR6] Penicillin-binding proteins (PBPs) function in the late steps of murein biosynthesis. Beta-lactams inactivate the PBPs by acylating an essential serine residue in the active site of these proteins.
== 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/py/1pyy_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1pyy ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
PBP2x is a primary determinant of beta-lactams resistance in Streptococcus pneumoniae. Altered PBP2x with multiple mutations have a reduced "affinity" for the antibiotics. An important polymorphism is found in PBP2x sequences from clinical resistant strains. To understand the mechanism of resistance, it is necessary to identify and characterize the relevant substitutions. Many similar PBP2x sequences from resistant isolates have the previously studied T338A mutation, adjacent to the active site Ser337. We report here the structural and functional analysis of the M339F substitution that is found in a subset of these sequences, originating from highly resistant strains. The M339F mutation causes a 4-10-fold reduction of the reaction rate with beta-lactams, depending on the molecular context. In addition, release of the inactivated antibiotic from the active site is up to 3-fold faster as a result from the M339F mutation. These effects measured in vitro are correlated with the level of beta-lactam resistance in vivo conferred by several PBP2x variants. Thus, a single amino acid difference between similar PBP2x from clinical isolates can strongly modulate the degree of beta-lactam resistance. The crystal structure of the double mutant T338A/M339F solved to a resolution of 2.4 A shows a distortion of the active site and a reorientation of the hydroxyl group of the active site Ser337, which can explain the kinetic effects of the mutations.

The structural modifications induced by the M339F substitution in PBP2x from Streptococcus pneumoniae further decreases the susceptibility to beta-lactams of resistant strains.,Chesnel L, Pernot L, Lemaire D, Champelovier D, Croize J, Dideberg O, Vernet T, Zapun A J Biol Chem. 2003 Nov 7;278(45):44448-56. Epub 2003 Aug 15. PMID:12923202<ref>PMID:12923202</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1pyy" style="background-color:#fffaf0;"></div>

==See Also==
*[[Penicillin-binding protein 3D structures|Penicillin-binding protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptococcus pneumoniae R6]]
[[Category: Champelovier D]]
[[Category: Chesnel L]]
[[Category: Croize J]]
[[Category: Dideberg O]]
[[Category: Lemaire D]]
[[Category: Pernot L]]
[[Category: Vernet T]]
[[Category: Zapun A]]