|
|
| (2 intermediate revisions not shown.) |
| Line 1: |
Line 1: |
| | | | |
| | ==Crystal structure of the GTP-bound wild type EhRabX3 from Entamoeba histolytica== | | ==Crystal structure of the GTP-bound wild type EhRabX3 from Entamoeba histolytica== |
| - | <StructureSection load='5c1t' size='340' side='right' caption='[[5c1t]], [[Resolution|resolution]] 2.80Å' scene=''> | + | <StructureSection load='5c1t' size='340' side='right'caption='[[5c1t]], [[Resolution|resolution]] 2.80Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5c1t]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5C1T OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5C1T FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5c1t]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Entamoeba_histolytica Entamoeba histolytica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5C1T OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5C1T FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GTP:GUANOSINE-5-TRIPHOSPHATE'>GTP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.801Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5c1s|5c1s]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GTP:GUANOSINE-5-TRIPHOSPHATE'>GTP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5c1t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5c1t OCA], [http://pdbe.org/5c1t PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5c1t RCSB], [http://www.ebi.ac.uk/pdbsum/5c1t PDBsum]</span></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=5c1t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5c1t OCA], [https://pdbe.org/5c1t PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5c1t RCSB], [https://www.ebi.ac.uk/pdbsum/5c1t PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5c1t ProSAT]</span></td></tr> |
| | </table> | | </table> |
| - | <div style="background-color:#fffaf0;">
| + | == Function == |
| - | == Publication Abstract from PubMed == | + | [https://www.uniprot.org/uniprot/Q5NT25_ENTHI Q5NT25_ENTHI] |
| - | The enteric protozoan parasite, Entamoeba histolytica, is the causative agent of amoebic dysentery, liver abscess and colitis in human. Vesicular trafficking plays a key role in the survival and virulence of the protozoan and is regulated by various Rab GTPases. EhRabX3 is a catalytically inefficient amoebic Rab protein, which is unique among the eukaryotic Ras superfamily by virtue of its tandem domain organization. Here, we report the crystal structures of GDP-bound fast hydrolyzing mutant (V71A/K73Q) and GTP-bound wild type EhRabX3 at 3.1 and 2.8A resolutions, respectively. Though both G-domains possess "phosphate binding loop containing nucleoside triphosphate hydrolases fold", only the N-terminal domain binds to guanine nucleotide. The relative orientation of the N-terminal domain and C-terminal domain is stabilized by numerous inter-domain interactions. Compared to other Ras superfamily members, both the GTPase domains displayed large deviation in switch II perhaps due to non-conservative substitutions in this region. As a result, entire switch II is restructured and moved away from the nucleotide binding pocket, providing a rationale for the diminished GTPase activity of EhRabX3. The N-terminal GTPase domain possesses unusually large number of cysteine residues. X-ray crystal structure of the fast hydrolyzing mutant of EhRabX3 revealed that C39 and C163 formed an intra-molecular disulfide bond. Subsequent mutational and biochemical studies suggest that C39 and C163 are critical for maintaining the structural integrity and function of EhRabX3. Structure-guided functional investigation of cysteine mutants could provide the physiological implications of the disulfide bond and could allow us to design potential inhibitors for the better treatment of intestinal amebiasis.
| + | |
| - | | + | |
| - | Crystal Structure Analysis of Wild Type and Fast Hydrolyzing Mutant of EhRabX3, a Tandem Ras Superfamily GTPase from Entamoeba histolytica.,Srivastava VK, Chandra M, Saito-Nakano Y, Nozaki T, Datta S J Mol Biol. 2016 Jan 16;428(1):41-51. doi: 10.1016/j.jmb.2015.11.003. Epub 2015, Nov 10. PMID:26555751<ref>PMID:26555751</ref>
| + | |
| - | | + | |
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| + | |
| - | </div>
| + | |
| - | <div class="pdbe-citations 5c1t" style="background-color:#fffaf0;"></div>
| + | |
| - | == References ==
| + | |
| - | <references/>
| + | |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Chandra, M]] | + | [[Category: Entamoeba histolytica]] |
| - | [[Category: Datta, S]] | + | [[Category: Large Structures]] |
| - | [[Category: Srivastava, V K]] | + | [[Category: Chandra M]] |
| - | [[Category: Hydrolase]] | + | [[Category: Datta S]] |
| - | [[Category: P-loop containing nucleotide triphosphate hydrolases fold]] | + | [[Category: Srivastava VK]] |
| - | [[Category: Tandem gtpase]]
| + | |
