9xae

Cryo-EM structure of the pre-40S ribosome (Enp1-Rrp12 WT) from Chaetomium thermophilum, state Rio2-C

spinqualitylabelsall models 9xae, resolution 3.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9xae is a 10 chain structure with sequence from Chaetomium thermophilum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3Å Ligands: MG, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 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] 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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