==Crystal structure of human PGRP-IBETAC in complex with glycosamyl muramyl pentapeptide==

<StructureSection load='2eax' size='340' side='right' caption='[[2eax]], [[Resolution|resolution]] 2.10&Aring;' scene=''>

<table><tr><td colspan='2'>[[2eax]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EAX OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2EAX FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=AMV:METHYL+2-(ACETYLAMINO)-3-O-[(1R)-1-CARBOXYETHYL]-2-DEOXY-BETA-D-GLUCOPYRANOSIDE'>AMV</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2eax FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2eax OCA], [http://pdbe.org/2eax PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2eax RCSB], [http://www.ebi.ac.uk/pdbsum/2eax PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2eax ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/PGRP4_HUMAN PGRP4_HUMAN]] Pattern receptor that binds to murein peptidoglycans (PGN) of Gram-positive bacteria. Has bactericidal activity towards Gram-positive bacteria. May kill Gram-positive bacteria by interfering with peptidoglycan biosynthesis. Binds also to Gram-negative bacteria, and has bacteriostatic activity towards Gram-negative bacteria. Plays a role in innate immunity.<ref>PMID:16354652</ref>

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== Publication Abstract from PubMed ==

Peptidoglycan recognition proteins (PGRPs) are highly conserved pattern-recognition molecules of the innate immune system that bind bacterial peptidoglycans (PGNs), which are polymers of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) cross-linked by short peptide stems. Human PRGPs are bactericidal against pathogenic and nonpathogenic Gram-positive bacteria, but not normal flora bacteria. Like certain glycopeptide antibiotics (e.g., vancomycin), PGRPs kill bacteria by directly interacting with their cell wall PGN, thereby interfering with PGN maturation. To better understand the bactericidal mechanism of PGRPs, we determined the crystal structure of the C-terminal PGN-binding domain of human PGRP-I beta in complex with NAG-NAM-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala, a synthetic glycopeptide comprising a complete PGN repeat. This structure, in conjunction with the previously reported NMR structure of a dimeric PGN fragment, permitted identification of major conformational differences between free and PGRP-bound PGN with respect to the relative orientation of saccharide and peptide moieties. These differences provided structural insights into the bactericidal mechanism of human PGRPs. On the basis of molecular modeling, we propose that these proteins disrupt cell wall maturation not only by sterically encumbering access of biosynthetic enzymes to the nascent PGN chains, but also by locking PGN into a conformation that prevents formation of cross-links between peptide stems in the growing cell wall.

Structural insights into the bactericidal mechanism of human peptidoglycan recognition proteins.,Cho S, Wang Q, Swaminathan CP, Hesek D, Lee M, Boons GJ, Mobashery S, Mariuzza RA Proc Natl Acad Sci U S A. 2007 May 22;104(21):8761-6. Epub 2007 May 14. PMID:17502600<ref>PMID:17502600</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 2eax" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Human]]

[[Category: Cho, S]]

[[Category: Peptidoglycan-binding protein]]