1m2v: Difference between revisions

[[Image:1m2v.gif|left|200px]]<br /><applet load="1m2v" size="350" color="white" frame="true" align="right" spinBox="true"  

COPII-coated vesicles form on the endoplasmic reticulum by the stepwise recruitment of three cytosolic components: Sar1-GTP to initiate coat formation, Sec23/24 heterodimer to select SNARE and cargo molecules, and Sec13/31 to induce coat polymerization and membrane deformation. Crystallographic analysis of the Saccharomyces cerevisiae Sec23/24-Sar1 complex reveals a bow-tie-shaped structure, 15 nm long, with a membrane-proximal surface that is concave and positively charged to conform to the size and acidic-phospholipid composition of the COPII vesicle. Sec23 and Sar1 form a continuous surface stabilized by a non-hydrolysable GTP analogue, and Sar1 has rearranged from the GDP conformation to expose amino-terminal residues that will probably embed in the bilayer. The GTPase-activating protein (GAP) activity of Sec23 involves an arginine side chain inserted into the Sar1 active site. These observations establish the structural basis for GTP-dependent recruitment of a vesicular coat complex, and for uncoating through coat-controlled GTP hydrolysis.

1M2V is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M2V OCA].  

[[Category: Corpina, R A.]]

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