4tmw: Difference between revisions
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''' | ==Translation initiation factor eIF5B (517-858) from C. thermophilum, bound to GTP and Sodium== | ||
<StructureSection load='4tmw' size='340' side='right' caption='[[4tmw]], [[Resolution|resolution]] 1.55Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4tmw]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TMW OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4TMW FirstGlance]. <br> | |||
</td></tr><tr><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>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene><br> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4tmw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4tmw OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4tmw RCSB], [http://www.ebi.ac.uk/pdbsum/4tmw 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®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Ficner, F.]] | |||
[[Category: Kuhle, B.]] | |||
[[Category: Gtpase]] | |||
[[Category: Ribosome]] | |||
[[Category: Subunit joining]] | |||
[[Category: Translation factor]] |