View source for 9xab


==Cryo-EM structure of the pre-40S ribosome (Enp1-Rrp12 WT) from Chaetomium thermophilum, state Tsr1-3==
<StructureSection load='9xab' size='340' side='right'caption='[[9xab]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9xab]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Chaetomium_thermophilum Chaetomium thermophilum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9XAB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9XAB 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]] 3.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=9xab FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9xab OCA], [https://pdbe.org/9xab PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9xab RCSB], [https://www.ebi.ac.uk/pdbsum/9xab PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9xab ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/G0RYF9_THET3 G0RYF9_THET3] 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.[HAMAP-Rule:MF_03015]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The decoding center (DC) is a key ribosomal structure for accurate translation, assembled in a multi-step process that starts on nucleolar pre-ribosomes and ends in the cytoplasm. While late cytoplasmic steps and their checkpoint mechanisms are well characterized, the regulation of early nucleoplasmic DC assembly is unclear. Here, we show that the essential assembly factor Rrp12 plays a central coordinating role. Using Chaetomium thermophilum and cryo-electron microscopy analyses of fifteen pre-40S intermediates, we demonstrate that Rrp12 C terminus truncation: (1) inhibits release of the Utp14-Dhr1 pair, (2) displaces Tsr1, (3) promotes premature stabilization of h28, and (4) prevents h44 formation. These defects impair final 18S rRNA processing and prematurely activate the quality control kinase Rio1. Our results reveal a nucleoplasmic checkpoint during DC formation and establish Rrp12 as a critical regulator ensuring accurate assembly and orderly ribosome maturation.

Nucleoplasmic checkpoint of the 40S ribosomal decoding center maturation.,Lau B, Li Y, Zhu J, Ye X, Fischer P, Hong X, Yuan R, Beckmann R, Hurt E, Cheng J Cell Rep. 2026 Jun 11;45(6):117545. doi: 10.1016/j.celrep.2026.117545. PMID:42275223<ref>PMID:42275223</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9xab" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Chaetomium thermophilum]]
[[Category: Large Structures]]
[[Category: Beckmann R]]
[[Category: Cheng J]]
[[Category: Fischer P]]
[[Category: Hong X]]
[[Category: Hurt E]]
[[Category: Lau B]]
[[Category: Li Y]]
[[Category: Yuan R]]
[[Category: Zhu J]]