View source for 1qts


==CRYSTAL STRUCTURE OF THE AP-2 CLATHRIN ADAPTOR ALPHA-APPENDAGE==
<StructureSection load='1qts' size='340' side='right'caption='[[1qts]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qts]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Lk3_transgenic_mice Lk3 transgenic mice]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QTS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QTS FirstGlance]. <br>
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1qtp|1qtp]]</div></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=1qts FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qts OCA], [https://pdbe.org/1qts PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qts RCSB], [https://www.ebi.ac.uk/pdbsum/1qts PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qts ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/AP2A2_MOUSE AP2A2_MOUSE]] Component of the adaptor protein complex 2 (AP-2). Adaptor protein complexes function in protein transport via transport vesicles in different membrane traffic pathways. Adaptor protein complexes are vesicle coat components and appear to be involved in cargo selection and vesicle formation. AP-2 is involved in clathrin-dependent endocytosis in which cargo proteins are incorporated into vesicles surrounded by clathrin (clathrin-coated vesicles, CCVs) which are destined for fusion with the early endosome. The clathrin lattice serves as a mechanical scaffold but is itself unable to bind directly to membrane components. Clathrin-associated adaptor protein (AP) complexes which can bind directly to both the clathrin lattice and to the lipid and protein components of membranes are considered to be the major clathrin adaptors contributing the CCV formation. AP-2 also serves as a cargo receptor to selectively sort the membrane proteins involved in receptor-mediated endocytosis. AP-2 seems to play a role in the recycling of synaptic vesicle membranes from the presynaptic surface. AP-2 recognizes Y-X-X-[FILMV] (Y-X-X-Phi) and [ED]-X-X-X-L-[LI] endocytosis signal motifs within the cytosolic tails of transmembrane cargo molecules. AP-2 may also play a role in maintaining normal post-endocytic trafficking through the ARF6-regulated, non-clathrin pathway. The AP-2 alpha subunit binds polyphosphoinositide-containing lipids, positioning AP-2 on the membrane. The AP-2 alpha subunit acts via its C-terminal appendage domain as a scaffolding platform for endocytic accessory proteins. The AP-2 alpha and AP-2 sigma subunits are thought to contribute to the recognition of the [ED]-X-X-X-L-[LI] motif.<ref>PMID:10459011</ref> <ref>PMID:14745134</ref> <ref>PMID:15473838</ref>  
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/qt/1qts_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1qts ConSurf].
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== Publication Abstract from PubMed ==
AP-2 adaptors regulate clathrin-bud formation at the cell surface by recruiting clathrin trimers to the plasma membrane and by selecting certain membrane proteins for inclusion within the developing clathrin-coat structure. These functions are performed by discrete subunits of the adaptor heterotetramer. The carboxyl-terminal appendage of the AP-2 alpha subunit appears to regulate the translocation of several endocytic accessory proteins to the bud site. We have determined the crystal structure of the alpha appendage at 1.4-A resolution by multiwavelength anomalous diffraction phasing. It is composed of two distinct structural modules, a beta-sandwich domain and a mixed alpha-beta platform domain. Structure-based mutagenesis shows that alterations to the molecular surface of a highly conserved region on the platform domain differentially affect associations of the appendage with amphiphysin, eps15, epsin, and AP180, revealing a common protein-binding interface.

Crystal structure of the alpha appendage of AP-2 reveals a recruitment platform for clathrin-coat assembly.,Traub LM, Downs MA, Westrich JL, Fremont DH Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8907-12. PMID:10430869<ref>PMID:10430869</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 1qts" style="background-color:#fffaf0;"></div>

==See Also==
*[[Adaptin 3D structures|Adaptin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Lk3 transgenic mice]]
[[Category: Downs, M A]]
[[Category: Fremont, D H]]
[[Category: Traub, L M]]
[[Category: Westrich, J L]]
[[Category: Four-wavelength mad]]
[[Category: Membrane protein]]
[[Category: Selenomethionine]]