Structure of a eukaryotic cytoplasmic pre‐40S ribosomal subunit

• DOI: 10.15252/embj.201798499
• Publication Date: 2018-02-20T01:10:20Z
• Authors: Alain Scaiola; Cohue Peña; Melanie Weisser; Daniel Böhringer; Marc Leibundgut; Purnima Klingauf‐...; Stefan Gerhardy; Vikram Govind Panse; Nenad Ban
• Keywords: Ribosomal Proteins; 0301 basic medicine; Cytoplasm; RNA Folding; Saccharomyces cerevisiae Proteins; Protein Conformation; 610 Medicine & health; Saccharomyces cerevisiae; Protein Serine-Threonine Kinases; 03 medical and health sciences; Protein Domains; 1300 General Biochemistry, Genetics and Molecular Biology; 2400 General Immunology and Microbiology; 1312 Molecular Biology; Protein Interaction Domains and Motifs; Ribosome Subunits, Small, Eukaryotic; 0303 health sciences; 10179 Institute of Medical Microbiology; Cryoelectron Microscopy; 2800 General Neuroscience; Nuclear Proteins; RNA-Binding Proteins; Molecular Docking Simulation; RNA, Ribosomal; 570 Life sciences; biology

AbstractFinal maturation of eukaryotic ribosomes occurs in the cytoplasm and requires the sequential removal of associated assembly factors and processing of the immature 20S pre-RNA. Using cryo-electron microscopy (cryo-EM), we have determined the structure of a cytoplasmic pre-40S particle poised to initiate final maturation at a resolution of 3.4 Å. The structure reveals the extent of conformational rearrangements of the 3’ major and 3’ minor domains of the ribosomal RNA that take place during maturation, as well as the roles of the assembly factors Enp1, Ltv1, Rio2, Tsr1, and Pno1 in the process. Altogether, we provide a structural framework for the coordination of the final maturation events that drive a pre-40S particle towards the mature form capable of engaging in translation.