Nmd3 is a structural mimic of eIF5A, and activates the cpGTPase Lsg1 during 60S ribosome biogenesis
| Autor: | Joachim Frank, Stephanie Patchett, Andrey G. Malyutin, Sharmishtha Musalgaonkar, Arlen W. Johnson |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Quality Control Ribosomal Proteins General Immunology and Microbiology General Neuroscience Protein subunit E-site Ribosome biogenesis Eukaryota GTPase Articles Biology Ribosome General Biochemistry Genetics and Molecular Biology Cell biology 03 medical and health sciences 030104 developmental biology Eukaryotic Cells Biochemistry Ribosome Subunits P-site Organelle biogenesis Molecular Biology Ribosomes |
| Popis: | During ribosome biogenesis in eukaryotes, nascent subunits are exported to the cytoplasm in a functionally inactive state. 60S subunits are activated through a series of cytoplasmic maturation events. The last known events in the cytoplasm are the release of Tif6 by Efl1 and Sdo1 and the release of the export adapter, Nmd3, by the GTPase Lsg1. Here, we have used cryo‐electron microscopy to determine the structure of the 60S subunit bound by Nmd3, Lsg1, and Tif6. We find that a central domain of Nmd3 mimics the translation elongation factor eIF5A, inserting into the E site of the ribosome and pulling the L1 stalk into a closed position. Additional domains occupy the P site and extend toward the sarcin–ricin loop to interact with Tif6. Nmd3 and Lsg1 together embrace helix 69 of the B2a intersubunit bridge, inducing base flipping that we suggest may activate the GTPase activity of Lsg1. |
| Databáze: | OpenAIRE |
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