Dynamic association of human Ebp1 with the ribosome

• Published in: RNA (Cambridge) 2021-04, Vol.27 (4), p.411-419
• Main Authors: Bhaskar, Varun, Desogus, Jessica, Graff-Meyer, Alexandra, Schenk, Andreas D, Cavadini, Simone, Chao, Jeffrey A
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing - chemistry; Adaptor Proteins, Signal Transducing - genetics; Adaptor Proteins, Signal Transducing - metabolism; Aminopeptidase; Binding Sites; Cryoelectron Microscopy; EBP1 protein; Homology; Humans; Macromolecules; Methionine; Models, Molecular; Protein Binding; Protein biosynthesis; Protein Biosynthesis - drug effects; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; Protein Synthesis Inhibitors - pharmacology; Puromycin; Puromycin - pharmacology; Ribosomal proteins; Ribosomal Proteins - chemistry; Ribosomal Proteins - genetics; Ribosomal Proteins - metabolism; Ribosomes; Ribosomes - chemistry; Ribosomes - genetics; Ribosomes - metabolism; RNA, Ribosomal - chemistry; RNA, Ribosomal - genetics; RNA, Ribosomal - metabolism; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; rRNA 28S; Thermodynamics
• ISSN: 1355-8382; 1469-9001
• DOI: 10.1261/rna.077602.120

Ribosomes are the macromolecular machines at the heart of protein synthesis; however, their function can be modulated by a variety of additional protein factors that directly interact with them. Here, we report the cryo-EM structure of human Ebp1 (p48 isoform) bound to the human 80S ribosome at 3.3 Å resolution. Ebp1 binds in the vicinity of the peptide exit tunnel on the 80S ribosome, and this binding is enhanced upon puromycin-mediated translational inhibition. The association of Ebp1 with the 80S ribosome centers around its interaction with ribosomal proteins eL19 and uL23 and the 28S rRNA. Further analysis of the Ebp1-ribosome complex suggests that Ebp1 can rotate around its insert domain, which may enable it to assume a wide range of conformations while maintaining its interaction with the ribosome. Structurally, Ebp1 shares homology with the methionine aminopeptidase 2 family of enzymes; therefore, this inherent flexibility may also be conserved.