View source for 6gsm


==Structure of a partial yeast 48S preinitiation complex in open conformation==
<SX load='6gsm' size='340' side='right' viewer='molstar' caption='[[6gsm]], [[Resolution|resolution]] 5.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6gsm]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Kluyveromyces_lactis Kluyveromyces lactis], [https://en.wikipedia.org/wiki/Kluyveromyces_lactis_NRRL_Y-1140 Kluyveromyces lactis NRRL Y-1140] and [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_S288C Saccharomyces cerevisiae S288C]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=3jaq 3jaq]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6GSM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6GSM FirstGlance]. <br>
</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=7NO:[(2~{R},3~{S},4~{R},5~{R})-5-(6-aminopurin-9-yl)-4-oxidanyl-2-(phosphonooxymethyl)oxolan-3-yl]+(2~{S})-2-azanyl-4-methylsulfanyl-butanoate'>7NO</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=MG:MAGNESIUM+ION'>MG</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=6gsm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6gsm OCA], [https://pdbe.org/6gsm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6gsm RCSB], [https://www.ebi.ac.uk/pdbsum/6gsm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6gsm 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 ==
The eukaryotic initiation factor 3 (eIF3) complex is involved in every step of translation initiation, but there is limited understanding of its molecular functions. Here, we present a single particle electron cryomicroscopy (cryo-EM) reconstruction of yeast 48S ribosomal preinitiation complex (PIC) in an open conformation conducive to scanning, with core subunit eIF3b bound on the 40S interface near the decoding center in contact with the ternary complex eIF2.GTP.initiator tRNA. eIF3b is relocated together with eIF3i from their solvent interface locations observed in other PIC structures, with eIF3i lacking 40S contacts. Re-processing of micrographs of our previous 48S PIC in a closed state also suggests relocation of the entire eIF3b-3i-3g-3a-Cter module during the course of initiation. Genetic analysis indicates that high fidelity initiation depends on eIF3b interactions at the 40S subunit interface that promote the closed PIC conformation, or facilitate the relocation of eIF3b/eIF3i to the solvent interface, on start codon selection.

Large-scale movement of eIF3 domains during translation initiation modulate start codon selection.,Llacer JL, Hussain T, Dong J, Villamayor L, Gordiyenko Y, Hinnebusch AG Nucleic Acids Res. 2021 Oct 14. pii: 6396891. doi: 10.1093/nar/gkab908. PMID:34648019<ref>PMID:34648019</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 6gsm" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribosome 3D structures|Ribosome 3D structures]]
== References ==
<references/>
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[[Category: Kluyveromyces lactis]]
[[Category: Kluyveromyces lactis NRRL Y-1140]]
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae S288C]]
[[Category: Gordiyenko Y]]
[[Category: Hussain T]]
[[Category: Llacer JL]]
[[Category: Ramakrishnan V]]