5abx: Difference between revisions

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'''Unreleased structure'''
==Complex of C. elegans eIF4E-3 with the 4E-binding protein Mextli and cap analog==
<StructureSection load='5abx' size='340' side='right' caption='[[5abx]], [[Resolution|resolution]] 1.66&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5abx]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5ABX OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5ABX FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MGP:7-METHYL-GUANOSINE-5-TRIPHOSPHATE'>MGP</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5abu|5abu]], [[5abv|5abv]], [[5aby|5aby]]</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=5abx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5abx OCA], [http://www.rcsb.org/pdb/explore.do?structureId=5abx RCSB], [http://www.ebi.ac.uk/pdbsum/5abx PDBsum]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/IF4E3_CAEEL IF4E3_CAEEL]] Recognizes and binds the 7-methylguanosine-containing mRNA cap during an early step in the initiation of protein synthesis and facilitates ribosome binding by inducing the unwinding of the mRNAs secondary structures. All 5 eIF4E proteins bind monomethyl cap structures. Only ife-1, ife-2 and ife-5 bind trimethyl cap structures which result from trans-splicing. Translation of trimethyl cap structure mRNAs may be regulated by intracellular redox state; disulfide bonds change the width and depth of the cap-binding cavity determining selectivity to mRNA caps. Ife-3 is essential for viability.<ref>PMID:10744754</ref> <ref>PMID:12422237</ref> <ref>PMID:9553113</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The eIF4E-binding proteins (4E-BPs) are a diverse class of translation regulators that share a canonical eIF4E-binding motif (4E-BM) with eIF4G. Consequently, they compete with eIF4G for binding to eIF4E, thereby inhibiting translation initiation. Mextli (Mxt) is an unusual 4E-BP that promotes translation by also interacting with eIF3. Here we present the crystal structures of the eIF4E-binding regions of the Drosophila melanogaster (Dm) and Caenorhabditis elegans (Ce) Mxt proteins in complex with eIF4E in the cap-bound and cap-free states. The structures reveal unexpected evolutionary plasticity in the eIF4E-binding mode, with a classical bipartite interface for Ce Mxt and a novel tripartite interface for Dm Mxt. Both interfaces comprise a canonical helix and a noncanonical helix that engage the dorsal and lateral surfaces of eIF4E, respectively. Remarkably, Dm Mxt contains a C-terminal auxiliary helix that lies anti-parallel to the canonical helix on the eIF4E dorsal surface. In contrast to the eIF4G and Ce Mxt complexes, the Dm eIF4E-Mxt complexes are resistant to competition by bipartite 4E-BPs, suggesting that Dm Mxt can bind eIF4E when eIF4G binding is inhibited. Our results uncovered unexpected diversity in the binding modes of 4E-BPs, resulting in eIF4E complexes that display differential sensitivity to 4E-BP regulation.


The entry 5abx is ON HOLD  until Paper Publication
Mextli proteins use both canonical bipartite and novel tripartite binding modes to form eIF4E complexes that display differential sensitivity to 4E-BP regulation.,Peter D, Weber R, Kone C, Chung MY, Ebertsch L, Truffault V, Weichenrieder O, Igreja C, Izaurralde E Genes Dev. 2015 Aug 20. PMID:26294658<ref>PMID:26294658</ref>


Authors: Peter, D., Weichenrieder, O.
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 
</div>
Description: Complex of C. elegans eIF4E-3 with the 4E-binding protein Mextli and cap analog
== References ==
[[Category: Unreleased Structures]]
<references/>
__TOC__
</StructureSection>
[[Category: Peter, D]]
[[Category: Peter, D]]
[[Category: Weichenrieder, O]]
[[Category: Weichenrieder, O]]
[[Category: 4e binding protein]]
[[Category: Cap binding protein]]
[[Category: Gene regulation]]
[[Category: Translation]]

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