View source for 1g16


==CRYSTAL STRUCTURE OF SEC4-GDP==
<StructureSection load='1g16' size='340' side='right'caption='[[1g16]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1g16]] is a 4 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=1G16 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1G16 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</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=1g16 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g16 OCA], [https://pdbe.org/1g16 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1g16 RCSB], [https://www.ebi.ac.uk/pdbsum/1g16 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1g16 ProSAT]</span></td></tr>
</table>
== 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/g1/1g16_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1g16 ConSurf].
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== Publication Abstract from PubMed ==
We have determined crystal structures of Sec4, a member of the Rab family in the G protein superfamily, in two states: bound to GDP, and to a non-hydrolyzable GTP analog, guanosine-5'-(beta, gamma)-imidotriphosphate (GppNHp). This represents the first structure of a Rab protein bound to GDP. Sec4 in both states grossly resembles other G proteins bound to GDP and GppNHp. In Sec4-GppNHp, structural features common to active Rab proteins are observed. In Sec4-GDP, the switch I region is highly disordered and displaced relative to the switch I region of Ras-GDP. In two of the four molecules of Sec4-GDP in the asymmetric unit of the Sec4-GDP crystals, the switch II region adopts a conformation similar to that seen in the structure of the small G protein Ran bound to GDP. This allows residues threonine 76, glutamate 80, and arginine 81 of Sec4 to make contacts with other conserved residues and water molecules important for nucleotide binding. In the other two molecules in the asymmetric unit, these interactions do not take place. This structural variability in both the switch I and switch II regions of GDP-bound Sec4 provides a possible explanation for the high off-rate of GDP bound to Sec4, and suggests a mechanism for regulation of the GTPase cycle of Rab proteins by GDI proteins.

Crystal structures of a Rab protein in its inactive and active conformations.,Stroupe C, Brunger AT J Mol Biol. 2000 Dec 8;304(4):585-98. PMID:11099382<ref>PMID:11099382</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 1g16" style="background-color:#fffaf0;"></div>

==See Also==
*[[GTP-binding protein 3D structures|GTP-binding protein 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Brunger AT]]
[[Category: Stroupe C]]