View source for 4tmv


==Translation initiation factor eIF5B (517-858) from C. thermophilum, bound to GTPgammaS and Sodium==
<StructureSection load='4tmv' size='340' side='right' caption='[[4tmv]], [[Resolution|resolution]] 1.53&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4tmv]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TMV OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4TMV FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=GSP:5-GUANOSINE-DIPHOSPHATE-MONOTHIOPHOSPHATE'>GSP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=4tmv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4tmv OCA], [http://pdbe.org/4tmv PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4tmv RCSB], [http://www.ebi.ac.uk/pdbsum/4tmv PDBsum]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Translational GTPases are universally conserved GTP hydrolyzing enzymes, critical for fidelity and speed of ribosomal protein biosynthesis. Despite their central roles, the mechanisms of GTP-dependent conformational switching and GTP hydrolysis that govern the function of trGTPases remain poorly understood. Here, we provide biochemical and high-resolution structural evidence that eIF5B and aEF1A/EF-Tu bound to GTP or GTPgammaS coordinate a monovalent cation (M+) in their active site. Our data reveal that M+ ions form constitutive components of the catalytic machinery in trGTPases acting as structural cofactor to stabilize the GTP-bound "on" state. Additionally, the M+ ion provides a positive charge into the active site analogous to the arginine-finger in the Ras-RasGAP system indicating a similar role as catalytic element that stabilizes the transition state of the hydrolysis reaction. In sequence and structure, the coordination shell for the M+ ion is, with exception of eIF2gamma, highly conserved among trGTPases from bacteria to human. We therefore propose a universal mechanism of M+-dependent conformational switching and GTP hydrolysis among trGTPases with important consequences for the interpretation of available biochemical and structural data.

A monovalent cation acts as structural and catalytic cofactor in translational GTPases.,Kuhle B, Ficner R EMBO J. 2014 Sep 15. pii: e201488517. PMID:25225612<ref>PMID:25225612</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4tmv" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Ficner, R]]
[[Category: Kuhle, B]]
[[Category: Gtpase]]
[[Category: Initiation factor]]
[[Category: Ribosome]]
[[Category: Translation]]