9XAG
Cryo-EM structure of the 90S pre-ribosome (Enp1-Rrp12 Mut) from Chaetomium thermophilum, state B1
This is a non-PDB format compatible entry.
Summary for 9XAG
| Entry DOI | 10.2210/pdb9xag/pdb |
| EMDB information | 66686 |
| Descriptor | Periodic tryptophan protein 2-like protein, U3 small nucleolar RNA-associated protein 13 C-terminal domain-containing protein, UTP14, ... (65 entities in total) |
| Functional Keywords | 90s pre-ribosome, rrp12, enp1, ribosome biogenesis, ribosome |
| Biological source | Thermochaetoides thermophila More |
| Total number of polymer chains | 66 |
| Total formula weight | 4490676.77 |
| Authors | Lau, B.,Li, Y.,Zhu, J.,Fischer, P.,Hong, X.,Yuan, R.,Beckmann, R.,Hurt, E.,Cheng, J. (deposition date: 2025-10-22, release date: 2026-06-24) |
| Primary citation | Lau, B.,Li, Y.,Zhu, J.,Ye, X.,Fischer, P.,Hong, X.,Yuan, R.,Beckmann, R.,Hurt, E.,Cheng, J. Nucleoplasmic checkpoint of the 40S ribosomal decoding center maturation. Cell Rep, 45:117545-117545, 2026 Cited by PubMed Abstract: 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. PubMed: 42275223DOI: 10.1016/j.celrep.2026.117545 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.8 Å) |
Structure validation
No wwPDB Validation report is currently available for this entry.
