View source for 5nl7


==The crystal structure of the Actin Binding Domain (ABD) of alpha actinin from Entamoeba histolytica==
<StructureSection load='5nl7' size='340' side='right'caption='[[5nl7]], [[Resolution|resolution]] 2.48&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5nl7]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Entamoeba_histolytica Entamoeba histolytica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5NL7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5NL7 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]] 2.48&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</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=5nl7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5nl7 OCA], [https://pdbe.org/5nl7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5nl7 RCSB], [https://www.ebi.ac.uk/pdbsum/5nl7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5nl7 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C4LWU6_ENTH1 C4LWU6_ENTH1] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The actin cytoskeleton, a dynamic network of actin filaments and associated F-actin-binding proteins, is fundamentally important in eukaryotes. alpha-Actinins are major F-actin bundlers that are inhibited by Ca(2+) in nonmuscle cells. Here we report the mechanism of Ca(2+)-mediated regulation of Entamoeba histolytica alpha-actinin-2 (EhActn2) with features expected for the common ancestor of Entamoeba and higher eukaryotic alpha-actinins. Crystal structures of Ca(2+)-free and Ca(2+)-bound EhActn2 reveal a calmodulin-like domain (CaMD) uniquely inserted within the rod domain. Integrative studies reveal an exceptionally high affinity of the EhActn2 CaMD for Ca(2+), binding of which can only be regulated in the presence of physiological concentrations of Mg(2+) Ca(2+) binding triggers an increase in protein multidomain rigidity, reducing conformational flexibility of F-actin-binding domains via interdomain cross-talk and consequently inhibiting F-actin bundling. In vivo studies uncover that EhActn2 plays an important role in phagocytic cup formation and might constitute a new drug target for amoebic dysentery.

Calcium modulates the domain flexibility and function of an alpha-actinin similar to the ancestral alpha-actinin.,Pinotsis N, Zielinska K, Babuta M, Arolas JL, Kostan J, Khan MB, Schreiner C, Salmazo A, Ciccarelli L, Puchinger M, Gkougkoulia EA, Ribeiro EA Jr, Marlovits TC, Bhattacharya A, Djinovic-Carugo K Proc Natl Acad Sci U S A. 2020 Sep 8;117(36):22101-22112. doi:, 10.1073/pnas.1917269117. Epub 2020 Aug 26. PMID:32848067<ref>PMID:32848067</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5nl7" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Entamoeba histolytica]]
[[Category: Large Structures]]
[[Category: Djinovic-Carugo K]]
[[Category: Khan MB]]
[[Category: Pinotsis N]]