View source for 6fyx


==Structure of a partial yeast 48S preinitiation complex with eIF5 N-terminal domain (model C1)==
<SX load='6fyx' size='340' side='right' viewer='molstar' caption='[[6fyx]], [[Resolution|resolution]] 3.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6fyx]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Kluyveromyces_lactis_NRRL_Y-1140 Kluyveromyces lactis NRRL Y-1140] and [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6FYX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6FYX FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1MA:6-HYDRO-1-METHYLADENOSINE-5-MONOPHOSPHATE'>1MA</scene>, <scene name='pdbligand=1MG:1N-METHYLGUANOSINE-5-MONOPHOSPHATE'>1MG</scene>, <scene name='pdbligand=2MG:2N-METHYLGUANOSINE-5-MONOPHOSPHATE'>2MG</scene>, <scene name='pdbligand=5MC:5-METHYLCYTIDINE-5-MONOPHOSPHATE'>5MC</scene>, <scene name='pdbligand=7MG:7N-METHYL-8-HYDROGUANOSINE-5-MONOPHOSPHATE'>7MG</scene>, <scene name='pdbligand=AYA:N-ACETYLALANINE'>AYA</scene>, <scene name='pdbligand=C4J:(2~{S})-2-azanyl-4-[5-[(2~{S},3~{R},4~{S},5~{S})-3,4-bis(oxidanyl)-5-(phosphonooxymethyl)oxolan-2-yl]-3-methyl-2,6-bis(oxidanylidene)pyrimidin-1-yl]butanoic+acid'>C4J</scene>, <scene name='pdbligand=GCP:PHOSPHOMETHYLPHOSPHONIC+ACID+GUANYLATE+ESTER'>GCP</scene>, <scene name='pdbligand=H2U:5,6-DIHYDROURIDINE-5-MONOPHOSPHATE'>H2U</scene>, <scene name='pdbligand=M2G:N2-DIMETHYLGUANOSINE-5-MONOPHOSPHATE'>M2G</scene>, <scene name='pdbligand=MA6:6N-DIMETHYLADENOSINE-5-MONOPHOSHATE'>MA6</scene>, <scene name='pdbligand=MET:METHIONINE'>MET</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PSU:PSEUDOURIDINE-5-MONOPHOSPHATE'>PSU</scene>, <scene name='pdbligand=RIA:2-O-[(5-PHOSPHO)RIBOSYL]ADENOSINE-5-MONOPHOSPHATE'>RIA</scene>, <scene name='pdbligand=T6A:N-[N-(9-B-D-RIBOFURANOSYLPURIN-6-YL)CARBAMOYL]THREONINE-5-MONOPHOSPHATE'>T6A</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'>[https://proteopedia.org/fgij/fg.htm?mol=6fyx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6fyx OCA], [https://pdbe.org/6fyx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6fyx RCSB], [https://www.ebi.ac.uk/pdbsum/6fyx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6fyx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RSSA_KLULA RSSA_KLULA] Required for the assembly and/or stability of the 40S ribosomal subunit. Required for the processing of the 20S rRNA-precursor to mature 18S rRNA in a late step of the maturation of 40S ribosomal subunits.
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== Publication Abstract from PubMed ==
In eukaryotic translation initiation AUG recognition of the mRNA requires accommodation of Met-tRNAi in a 'PIN' state, which is antagonized by the factor eIF1. eIF5 is a GTPase activating protein (GAP) of eIF2 that additionally promotes stringent AUG selection, but the molecular basis of its dual function was unknown. We present a cryo-electron microscopy (cryo-EM) reconstruction of a yeast 48S pre-initiation complex (PIC), at an overall resolution of 3.0 A, featuring the N-terminal domain (NTD) of eIF5 bound to the 40S subunit at the location vacated by eIF1. eIF5 interacts with and allows a more accommodated orientation of Met-tRNAi. Substitutions of eIF5 residues involved in the eIF5-NTD/tRNAi interaction influenced initiation at near-cognate UUG codons in vivo, and the closed/open PIC conformation in vitro, consistent with direct stabilization of the codon:anticodon duplex by the wild-type eIF5-NTD. The present structure reveals the basis for a key role of eIF5 in start-codon selection.

Translational initiation factor eIF5 replaces eIF1 on the 40S ribosomal subunit to promote start-codon recognition.,Llacer JL, Hussain T, Saini AK, Nanda JS, Kaur S, Gordiyenko Y, Kumar R, Hinnebusch AG, Lorsch JR, Ramakrishnan V Elife. 2018 Nov 26;7. pii: 39273. doi: 10.7554/eLife.39273. PMID:30475211<ref>PMID:30475211</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6fyx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribosome 3D structures|Ribosome 3D structures]]
== References ==
<references/>
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</SX>
[[Category: Kluyveromyces lactis NRRL Y-1140]]
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Gordiyenko Y]]
[[Category: Hussain T]]
[[Category: Llacer JL]]
[[Category: Ramakrishnan V]]