5abx: Difference between revisions
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==Complex of C. elegans eIF4E-3 with the 4E-binding protein Mextli and cap analog== | ==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]] 1.66Å' scene=''> | <StructureSection load='5abx' size='340' side='right'caption='[[5abx]], [[Resolution|resolution]] 1.66Å' scene=''> | ||
== Structural highlights == | == 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 [ | <table><tr><td colspan='2'>[[5abx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Caenorhabditis_elegans Caenorhabditis elegans]. 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 [https://proteopedia.org/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='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.66Å</td></tr> | ||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5abx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5abx OCA], [https://pdbe.org/5abx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5abx RCSB], [https://www.ebi.ac.uk/pdbsum/5abx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5abx ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
[ | [https://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;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | </div> | ||
<div class="pdbe-citations 5abx" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Eukaryotic initiation factor 3D structures|Eukaryotic initiation factor 3D structures]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: | [[Category: Caenorhabditis elegans]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Peter D]] | ||
[[Category: | [[Category: Weichenrieder O]] | ||
Latest revision as of 14:39, 9 May 2024
Complex of C. elegans eIF4E-3 with the 4E-binding protein Mextli and cap analogComplex of C. elegans eIF4E-3 with the 4E-binding protein Mextli and cap analog
Structural highlights
FunctionIF4E3_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.[1] [2] [3] Publication Abstract from PubMedThe 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. 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[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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