8cas
From Proteopedia
Cryo-EM structure of native Otu2-bound ubiquitinated 48S initiation complex (partial)
Structural highlights
FunctionRSSA1_YEAST 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.[1] [2] Publication Abstract from PubMedIn actively translating 80S ribosomes the ribosomal protein eS7 of the 40S subunit is monoubiquitinated by the E3 ligase Not4 and deubiquitinated by Otu2 upon ribosomal subunit recycling. Despite its importance for translation efficiency the exact role and structural basis for this translational reset is poorly understood. Here, structural analysis by cryo-electron microscopy of native and reconstituted Otu2-bound ribosomal complexes reveals that Otu2 engages 40S subunits mainly between ribosome recycling and initiation stages. Otu2 binds to several sites on the intersubunit surface of the 40S that are not occupied by any other 40S-binding factors. This binding mode explains the discrimination against 80S ribosomes via the largely helical N-terminal domain of Otu2 as well as the specificity for mono-ubiquitinated eS7 on 40S. Collectively, this study reveals mechanistic insights into the Otu2-driven deubiquitination steps for translational reset during ribosome recycling/(re)initiation. Molecular basis for recognition and deubiquitination of 40S ribosomes by Otu2.,Ikeuchi K, Ivic N, Buschauer R, Cheng J, Frohlich T, Matsuo Y, Berninghausen O, Inada T, Becker T, Beckmann R Nat Commun. 2023 May 12;14(1):2730. doi: 10.1038/s41467-023-38161-w. PMID:37169754[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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