View source for 9r4v


==Solution structure of N-WASP GBD in complex with EspF==
<StructureSection load='9r4v' size='340' side='right'caption='[[9r4v]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9r4v]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9R4V OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9R4V FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 20 models</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=9r4v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9r4v OCA], [https://pdbe.org/9r4v PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9r4v RCSB], [https://www.ebi.ac.uk/pdbsum/9r4v PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9r4v ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/WASL_HUMAN WASL_HUMAN] Regulates actin polymerization by stimulating the actin-nucleating activity of the Arp2/3 complex. Binds to HSF1/HSTF1 and forms a complex on heat shock promoter elements (HSE) that negatively regulates HSP90 expression.<ref>PMID:19366662</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
EspF is an enteropathogenic Escherichia coli (EPEC) effector protein that interferes with intestinal epithelial cell signaling by binding to the Src homology 3 (SH3) domain of sorting nexin 9 (SNX9) and the GTPase-binding domain (GBD) of neural Wiskott-Aldrich syndrome protein (N-WASP) with its C-terminal proline-rich repeats. To understand the molecular basis of these interactions, we characterized the structure, dynamics, and binding thermodynamics of EspF and its target protein domain complexes. We also elaborated on our previous study on EspF(U), a homologous effector in enterohemorrhagic E. coli (EHEC), and compared the two effectors. We show that EspF is intrinsically disordered but that NMR chemical shifts expose the pre-structured polyproline II (PPII) helical SH3- and helical GBD-binding motifs. These motifs mimic their cellular counterparts but are fine-tuned to prevail in competitive binding. Factors behind EspF's higher affinity for GBD relative to the cellular ligand are key residue mutations and a C-terminally elongated polar interaction interface. The latter compensates for the lack of an "extended arm", the critical substitution promoting high affinity for GBD in EspF(U). With this advantage, EspF outcompetes the autoinhibitory N-WASP C-helix and stimulates actin polymerization. EspF binds SNX9 SH3 with an extended binding interface, residues N-terminal to the RxAPxxP core motif being essential to strong binding. We define the SNX9 SH3-binding epitope as varphixPxRxAPxxP and propose to re-delineate the EPEC EspF repeat boundaries accordingly. Furthermore, a characteristic (13)C secondary chemical shift pattern is recognized as a fingerprint of polyproline II (PPII) helical conformation in the SH3 binding epitope.

Intrinsically disordered enteropathogenic E. coli EspF exploits motif mimicry in high-affinity binding to neural Wiskott-Aldrich syndrome protein and sorting nexin 9.,Tossavainen H, Karjalainen M, Antenucci L, Hellman M, Permi P Int J Biol Macromol. 2025 Oct 10;330(Pt 3):148227. doi: , 10.1016/j.ijbiomac.2025.148227. PMID:41075884<ref>PMID:41075884</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9r4v" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Permi P]]
[[Category: Tossavainen H]]