4h5i
From Proteopedia
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- | [[Image:4h5i.jpg|left|200px]] | ||
- | + | ==Crystal Structure of the Guanine Nucleotide Exchange Factor Sec12 (P1 form)== | |
+ | <StructureSection load='4h5i' size='340' side='right'caption='[[4h5i]], [[Resolution|resolution]] 1.36Å' scene=''> | ||
+ | == Structural highlights == | ||
+ | <table><tr><td colspan='2'>[[4h5i]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4H5I OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4H5I 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]] 1.36Å</td></tr> | ||
+ | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=4h5i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4h5i OCA], [https://pdbe.org/4h5i PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4h5i RCSB], [https://www.ebi.ac.uk/pdbsum/4h5i PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4h5i ProSAT]</span></td></tr> | ||
+ | </table> | ||
+ | == Function == | ||
+ | [https://www.uniprot.org/uniprot/SEC12_YEAST SEC12_YEAST] Guanine nucleotide-exchange factor (GEF) required for the formation or budding of transport vesicles from the ER. This function involves the cytoplasmic domain of the protein, which is thought to interact with the small GTP-binding protein SAR1. Required for autophagy.<ref>PMID:11694599</ref> <ref>PMID:12655150</ref> <ref>PMID:1327759</ref> <ref>PMID:16413259</ref> <ref>PMID:1649197</ref> <ref>PMID:1907973</ref> <ref>PMID:1907974</ref> <ref>PMID:1922074</ref> <ref>PMID:2512296</ref> <ref>PMID:3047151</ref> <ref>PMID:6996832</ref> <ref>PMID:7865879</ref> <ref>PMID:8106544</ref> <ref>PMID:8377826</ref> <ref>PMID:8583945</ref> <ref>PMID:9023343</ref> | ||
+ | <div style="background-color:#fffaf0;"> | ||
+ | == Publication Abstract from PubMed == | ||
+ | COPII-coated vesicles transport proteins and lipids from the endoplasmic reticulum to the Golgi. Crucial for the initiation of COPII coat assembly is Sec12, a guanine nucleotide exchange factor responsible for activating the small G protein Sar1. Once activated, Sar1/GTP binds to ER membranes and recruits COPII coat components (Sec23/24 and Sec13/31). Here, we report the 1.35 A resolution crystal structure of the catalytically active, 38-kDa cytoplasmic portion of Saccharomyces cerevisiae Sec12. Sec12 adopts a beta propeller fold. Conserved residues cluster around a loop we term the "K loop", which extends from the N-terminal propeller blade. Structure-guided site-directed mutagenesis, in conjunction with in vitro and in vivo functional studies, reveal that this region of Sec12 is catalytically essential, presumably because it makes direct contact with Sar1. Strikingly, the crystal structure also reveals that a single potassium ion stabilizes the K loop; bound potassium is, moreover, essential for optimum guanine nucleotide exchange activity in vitro. Thus, our results reveal a novel role for a potassium-stabilized loop in catalyzing guanine nucleotide exchange. | ||
- | + | The Structure of Sec12 Implicates Potassium Ion Coordination in Sar1 Activation.,McMahon C, Studer SM, Clendinen C, Dann GP, Jeffrey PD, Hughson FM J Biol Chem. 2012 Oct 29. PMID:23109340<ref>PMID:23109340</ref> | |
- | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
- | == | + | </div> |
- | + | <div class="pdbe-citations 4h5i" style="background-color:#fffaf0;"></div> | |
+ | == References == | ||
+ | <references/> | ||
+ | __TOC__ | ||
+ | </StructureSection> | ||
+ | [[Category: Large Structures]] | ||
[[Category: Saccharomyces cerevisiae]] | [[Category: Saccharomyces cerevisiae]] | ||
- | [[Category: Hughson | + | [[Category: Hughson FM]] |
- | [[Category: Jeffrey | + | [[Category: Jeffrey PD]] |
- | [[Category: McMahon | + | [[Category: McMahon C]] |
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Current revision
Crystal Structure of the Guanine Nucleotide Exchange Factor Sec12 (P1 form)
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