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New page: left|200px<br /><applet load="1nj4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nj4, resolution 1.90Å" /> '''Crystal structure of... |
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== | ==Crystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 1.9 A resolution== | ||
Penicillin-binding protein 5 (PBP 5) of Escherichia coli functions as a | <StructureSection load='1nj4' size='340' side='right'caption='[[1nj4]], [[Resolution|resolution]] 1.90Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1nj4]] 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=1NJ4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NJ4 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='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1nj4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nj4 OCA], [https://pdbe.org/1nj4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1nj4 RCSB], [https://www.ebi.ac.uk/pdbsum/1nj4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1nj4 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/DACA_ECOLI DACA_ECOLI] Removes C-terminal D-alanyl residues from sugar-peptide cell wall precursors. | |||
== 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/nj/1nj4_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=1nj4 ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Penicillin-binding protein 5 (PBP 5) of Escherichia coli functions as a d-alanine carboxypeptidase (CPase), cleaving d-alanine from the C terminus of cell wall peptides. Like all PBPs, PBP 5 forms a covalent acyl-enzyme complex with beta-lactam antibiotics; however, PBP 5 is distinguished by its high rate of deacylation of the acylenzyme complex (t(1/2) approximately 10 min). A Gly105 --> Asp mutation in PBP 5 markedly impairs deacylation with only minor effects on acylation, and abolishes CPase activity. We have determined the three-dimensional structure of a soluble form of wild-type PBP 5 at 1.85-A resolution and have also refined the structure of the G105D mutant form of PBP 5 to 1.9-A resolution. Comparison of the two structures reveals that the major effect of the mutation is to disorder a loop comprising residues 74-90 that sits atop the SXN motif of the active site. Deletion of the 74-90 loop in wild-type PBP 5 markedly diminished the deacylation rate of penicillin G with a minimal impact on acylation, and abolished CPase activity. These effects were very similar to those observed in the G105D mutant, reinforcing the idea that this mutation causes disordering of the 74-90 loop. Mutation of two consecutive serines within this loop, which hydrogen bond to Ser110 and Asn112 in the SXN motif, had marked effects on CPase activity, but not beta-lactam antibiotic binding or hydrolysis. These data suggest a direct role for the SXN motif in deacylation of the acyl-enzyme complex and imply that the functioning of this motif is modulated by the 74-90 loop. | |||
Crystal structure of wild-type penicillin-binding protein 5 from Escherichia coli: implications for deacylation of the acyl-enzyme complex.,Nicholas RA, Krings S, Tomberg J, Nicola G, Davies C J Biol Chem. 2003 Dec 26;278(52):52826-33. Epub 2003 Oct 10. PMID:14555648<ref>PMID:14555648</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
<div class="pdbe-citations 1nj4" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Penicillin-binding protein 3D structures|Penicillin-binding protein 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Davies C]] | |||
[[Category: Davies | [[Category: Nicholas RA]] | ||
[[Category: Nicholas | [[Category: Nicola G]] | ||
[[Category: Nicola | |||
Latest revision as of 12:20, 16 August 2023
Crystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 1.9 A resolutionCrystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 1.9 A resolution
Structural highlights
FunctionDACA_ECOLI Removes C-terminal D-alanyl residues from sugar-peptide cell wall precursors. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPenicillin-binding protein 5 (PBP 5) of Escherichia coli functions as a d-alanine carboxypeptidase (CPase), cleaving d-alanine from the C terminus of cell wall peptides. Like all PBPs, PBP 5 forms a covalent acyl-enzyme complex with beta-lactam antibiotics; however, PBP 5 is distinguished by its high rate of deacylation of the acylenzyme complex (t(1/2) approximately 10 min). A Gly105 --> Asp mutation in PBP 5 markedly impairs deacylation with only minor effects on acylation, and abolishes CPase activity. We have determined the three-dimensional structure of a soluble form of wild-type PBP 5 at 1.85-A resolution and have also refined the structure of the G105D mutant form of PBP 5 to 1.9-A resolution. Comparison of the two structures reveals that the major effect of the mutation is to disorder a loop comprising residues 74-90 that sits atop the SXN motif of the active site. Deletion of the 74-90 loop in wild-type PBP 5 markedly diminished the deacylation rate of penicillin G with a minimal impact on acylation, and abolished CPase activity. These effects were very similar to those observed in the G105D mutant, reinforcing the idea that this mutation causes disordering of the 74-90 loop. Mutation of two consecutive serines within this loop, which hydrogen bond to Ser110 and Asn112 in the SXN motif, had marked effects on CPase activity, but not beta-lactam antibiotic binding or hydrolysis. These data suggest a direct role for the SXN motif in deacylation of the acyl-enzyme complex and imply that the functioning of this motif is modulated by the 74-90 loop. Crystal structure of wild-type penicillin-binding protein 5 from Escherichia coli: implications for deacylation of the acyl-enzyme complex.,Nicholas RA, Krings S, Tomberg J, Nicola G, Davies C J Biol Chem. 2003 Dec 26;278(52):52826-33. Epub 2003 Oct 10. PMID:14555648[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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