5ll6
Structure of the 40S ABCE1 post-splitting complex in ribosome recycling and translation initiationStructure of the 40S ABCE1 post-splitting complex in ribosome recycling and translation initiation
Structural highlights
Function[RS7A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.[1] [RSSA1_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.[2] [3] [RS21A_YEAST] Required for the processing of the 20S rRNA-precursor to mature 18S rRNA in a late step of the maturation of 40S ribosomal subunits. Has a physiological role leading to 18S rRNA stability.[4] [RS6A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.[5] [RS9A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.[6] [RS14A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.[7] [RLI1_YEAST] Component of the multifactor complex (MFC) involved in translation initiation. Required for the binding of MFC to the 40S ribosome. Required for the processing and nuclear export of the 60S and 40S ribosomal subunits.[8] [9] [10] [RS2_YEAST] Important in the assembly and function of the 40S ribosomal subunit. Mutations in this protein affects the control of translational fidelity. Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.[11] Publication Abstract from PubMedThe essential ATP-binding cassette protein ABCE1 splits 80S ribosomes into 60S and 40S subunits after canonical termination or quality-control-based mRNA surveillance processes. However, the underlying splitting mechanism remains enigmatic. Here, we present a cryo-EM structure of the yeast 40S-ABCE1 post-splitting complex at 3.9-A resolution. Compared to the pre-splitting state, we observe repositioning of ABCE1's iron-sulfur cluster domain, which rotates 150 degrees into a binding pocket on the 40S subunit. This repositioning explains a newly observed anti-association activity of ABCE1. Notably, the movement implies a collision with A-site factors, thus explaining the splitting mechanism. Disruption of key interactions in the post-splitting complex impairs cellular homeostasis. Additionally, the structure of a native post-splitting complex reveals ABCE1 to be part of the 43S initiation complex, suggesting a coordination of termination, recycling, and initiation. Structure of the 40S-ABCE1 post-splitting complex in ribosome recycling and translation initiation.,Heuer A, Gerovac M, Schmidt C, Trowitzsch S, Preis A, Kotter P, Berninghausen O, Becker T, Beckmann R, Tampe R Nat Struct Mol Biol. 2017 Apr 3. doi: 10.1038/nsmb.3396. PMID:28368393[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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