View source for 6b3i


==Annexin A13a==
<StructureSection load='6b3i' size='340' side='right'caption='[[6b3i]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6b3i]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6B3I OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6B3I 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]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</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=6b3i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6b3i OCA], [https://pdbe.org/6b3i PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6b3i RCSB], [https://www.ebi.ac.uk/pdbsum/6b3i PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6b3i ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ANX13_HUMAN ANX13_HUMAN] Binds to membranes enriched in phosphatidylserine or phosphatidylglycerol in a calcium-dependent manner (PubMed:27676605, PubMed:30610115). Half-maximal membrane binding requires about 60 uM calcium. Does not bind to membranes that lack phospholipids with an acidic headgroup (PubMed:27676605).<ref>PMID:27676605</ref> <ref>PMID:30610115</ref>   Binds to membranes enriched in phosphatidylserine or phosphatidylglycerol in a calcium-dependent manner, but requires higher calcium levels for membrane binding than isoform A. Half-maximal membrane binding requires about 320 uM calcium.<ref>PMID:27676605</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Annexin proteins function as Ca(2+)-dependent regulators of membrane trafficking and repair that may also modulate membrane curvature. Here, using high-resolution confocal imaging, we report that the intestine-specific annexin A13 (ANX A13) localizes to the tips of intestinal microvilli and determined the crystal structure of the ANX A13a isoform to 2.6 A resolution. The structure revealed that the N terminus exhibits an alternative fold that converts the first two helices and the associated helix-loop-helix motif into a continuous alpha-helix, as stabilized by a domain-swapped dimer. We also found that the dimer is present in solution and partially occludes the membrane-binding surfaces of annexin, suggesting that dimerization may function as a means for regulating membrane binding. Accordingly, as revealed by in vitro binding and cellular localization assays, ANX A13a variants that favor a monomeric state exhibited increased membrane association relative to variants that favor the dimeric form. Together, our findings support a mechanism for how the association of the ANX A13a isoform with the membrane is regulated.

An alternative N-terminal fold of the intestine-specific annexin A13a induces dimerization and regulates membrane-binding.,McCulloch KM, Yamakawa I, Shifrin DA Jr, McConnell RE, Foegeding NJ, Singh PK, Mao S, Tyska MJ, Iverson TM J Biol Chem. 2019 Mar 8;294(10):3454-3463. doi: 10.1074/jbc.RA118.004571. Epub, 2019 Jan 4. PMID:30610115<ref>PMID:30610115</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6b3i" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Iverson TM]]
[[Category: McCulloch KM]]