View source for 7nsx


==Drosophila PGRP-LB wild-type==
<StructureSection load='7nsx' size='340' side='right'caption='[[7nsx]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7nsx]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Drosophila_melanogaster Drosophila melanogaster]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7NSX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7NSX 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=7nsx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7nsx OCA], [https://pdbe.org/7nsx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7nsx RCSB], [https://www.ebi.ac.uk/pdbsum/7nsx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7nsx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PGPLB_DROME PGPLB_DROME] N-acetylmuramyl-L-alanine amidase involved in innate immunity by degrading bacterial peptidoglycans (PGN). Probably plays a scavenger role by digesting biologically active PGN into biologically inactive fragments. Has no direct bacteriolytic activity.<ref>PMID:12845326</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Peptidoglycan recognition proteins (PGRPs) are ubiquitous among animals and play pivotal functions in insect immunity. Non-catalytic PGRPs are involved in the activation of immune pathways by binding to the peptidoglycan (PGN), whereas amidase PGRPs are capable of cleaving the PGN into non-immunogenic compounds. Drosophila PGRP-LB belongs to the amidase PGRPs and downregulates the immune deficiency (IMD) pathway by cleaving meso-2,6-diaminopimelic (meso-DAP or DAP)-type PGN. While the recognition process is well analyzed for the non-catalytic PGRPs, little is known about the enzymatic mechanism for the amidase PGRPs, despite their essential function in immune homeostasis. Here, we analyzed the specific activity of different isoforms of Drosophila PGRP-LB towards various PGN substrates to understand their specificity and role in Drosophila immunity. We show that these isoforms have similar activity towards the different compounds. To analyze the mechanism of the amidase activity, we performed site directed mutagenesis and solved the X-ray structures of wild-type Drosophila PGRP-LB and its mutants, with one of these structures presenting a protein complexed with the tracheal cytotoxin (TCT), a muropeptide derived from the PGN. Only the Y78F mutation abolished the PGN cleavage while other mutations reduced the activity solely. Together, our findings suggest the dynamic role of the residue Y78 in the amidase mechanism by nucleophilic attack through a water molecule to the carbonyl group of the amide function destabilized by Zn(2+).

PGRP-LB: An Inside View into the Mechanism of the Amidase Reaction.,Orlans J, Vincent-Monegat C, Rahioui I, Sivignon C, Butryn A, Soulere L, Zaidman-Remy A, Orville AM, Heddi A, Aller P, Da Silva P Int J Mol Sci. 2021 May 7;22(9). pii: ijms22094957. doi: 10.3390/ijms22094957. PMID:34066955<ref>PMID:34066955</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7nsx" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Drosophila melanogaster]]
[[Category: Large Structures]]
[[Category: Aller P]]
[[Category: Da Silva P]]
[[Category: Orlans J]]