View source for 4axg


==Structure of eIF4E-Cup complex==
<StructureSection load='4axg' size='340' side='right'caption='[[4axg]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4axg]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Drosophila_melanogaster Drosophila melanogaster]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AXG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AXG FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.8&#8491;</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=4axg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4axg OCA], [https://pdbe.org/4axg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4axg RCSB], [https://www.ebi.ac.uk/pdbsum/4axg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4axg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/IF4E_DROME IF4E_DROME] 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.<ref>PMID:8663200</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cup is an eIF4E-binding protein (4E-BP) that plays a central role in translational regulation of localized mRNAs during early Drosophila development. In particular, Cup is required for repressing translation of the maternally contributed oskar, nanos, and gurken mRNAs, all of which are essential for embryonic body axis determination. Here, we present the 2.8 A resolution crystal structure of a minimal eIF4E-Cup assembly, consisting of the interacting regions of the two proteins. In the structure, two separate segments of Cup contact two orthogonal faces of eIF4E. The eIF4E-binding consensus motif of Cup (YXXXXLPhi) binds the convex side of eIF4E similarly to the consensus of other eIF4E-binding proteins, such as 4E-BPs and eIF4G. The second, noncanonical, eIF4E-binding site of Cup binds laterally and perpendicularly to the eIF4E beta-sheet. Mutations of Cup at this binding site were shown to reduce binding to eIF4E and to promote the destabilization of the associated mRNA. Comparison with the binding mode of eIF4G to eIF4E suggests that Cup and eIF4G binding would be mutually exclusive at both binding sites. This shows how a common molecular surface of eIF4E might recognize different proteins acting at different times in the same pathway. The structure provides insight into the mechanism by which Cup disrupts eIF4E-eIF4G interaction and has broader implications for understanding the role of 4E-BPs in translational regulation.

Crystal structure of a minimal eIF4E-Cup complex reveals a general mechanism of eIF4E regulation in translational repression.,Kinkelin K, Veith K, Grunwald M, Bono F RNA. 2012 Sep;18(9):1624-34. Epub 2012 Jul 25. PMID:22832024<ref>PMID:22832024</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4axg" style="background-color:#fffaf0;"></div>

==See Also==
*[[Eukaryotic initiation factor 3D structures|Eukaryotic initiation factor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Drosophila melanogaster]]
[[Category: Large Structures]]
[[Category: Bono F]]
[[Category: Gruenwald M]]
[[Category: Kinkelin K]]
[[Category: Veith K]]