6y7c | pdb_00006y7c

Early cytoplasmic yeast pre-40S particle (purified with Tsr1 as bait)

spinqualitylabelsall models 6y7c, resolution 3.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6y7c is a 34 chain structure with sequence from Saccharomyces cerevisiae (strain atcc 204508 / s288c). Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: A2M Activity: Non-specific serine/threonine protein kinase, with EC number 2.7.11.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [RIO2_YEAST] Required for the final endonucleolytic cleavage of 20S pre-rRNA at site D in the cytoplasm, converting it into the mature 18S rRNA. Involved in normal export of the pre-40S particles from the nucleus to the cytoplasm. No longer associates with pre-40S subunits in RPS19 disruptions, suggesting it acts after the ribosomal protein in 18S rRNA maturation. [LTV1_YEAST] Involved in protein transport. Non-ribosomal factor required for efficient nuclear export of the ribosomal 40S subunit. Component of the GSE complex, a GTPase complex required for intracellular sorting of GAP1 out of the endosome. [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. [RS6A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly. [RS27A_YEAST] Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, and DNA-damage responses. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling (By similarity). 40S ribosomal protein S31 is a component of the 40S subunit of the ribosome (By similarity). [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. [RS18A_YEAST] Located at the top of the head of the 40S subunit, it contacts several helices of the 18S rRNA (By similarity).[HAMAP-Rule:MF_01315] [PNO1_YEAST] Required for small ribosomal subunit (SSU) synthesis. Has a role in the processing of early nucleolar and late cytoplasmic pre-RNA species. Recruits DIM1 to nucleolar pre-RNAs. Indirectly required for cleavage at the A2 site of the 20S pre-rRNA, forming 18S rRNA, and at A1 and A2 sites of other pre-rRNAs. [RS14A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly. [RS9A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly. [ENP1_YEAST] Required for normal export of the pre-40S particles from the nucleus to the cytoplasm. Its subcellular location and association with pre-40S subunit shifts from mixed cytoplasm/nucleus to all nuclear in RPS19 disruptions, suggesting it acts after the ribosomal protein. [RS15_YEAST] Involved in the nuclear export of the small ribosomal subunit. Has a role in the late stage of the assembly of pre-40S particles within the nucleus and controls their export to the cytoplasm. [RS7A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly. [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. [TSR1_YEAST] Required for 40S ribosomal subunit synthesis. Required for normal export of the pre-40S particles from the nucleus to the cytoplasm. Its subcellular location and association with pre-40S subunitshifts from mixed cytoplasm/nucleus to all nuclear in RPS19 disruptions, suggesting it acts after the ribosomal protein. [RS19A_YEAST] Required for proper maturation of the small (40S) ribosomal subunit. Binds to 40s pre-ribosomal particles, probably required after association of NOC4 but before association of ENP1, TSR1 and RIO2 with 20/21S pre-rRNA. Publication Abstract from PubMed Assembly of eukaryotic ribosomal subunits is a very complex and sequential process that starts in the nucleolus and finishes in the cytoplasm with the formation of functional ribosomes. Over the past few years, characterization of the many molecular events underlying eukaryotic ribosome biogenesis has been drastically improved by the "resolution revolution" of cryo-electron microscopy (cryo-EM). However, if very early maturation events have been well characterized for both yeast ribosomal subunits, little is known regarding the final maturation steps occurring to the small (40S) ribosomal subunit. To try to bridge this gap, we have used proteomics together with cryo-EM and single particle analysis to characterize yeast pre-40S particles containing the ribosome biogenesis factor Tsr1. Our analyses lead us to refine the timing of the early pre-40S particle maturation steps. Furthermore, we suggest that after an early and structurally stable stage, the beak and platform domains of pre-40S particles enter a "vibrating" or "wriggling" stage, that might be involved in the final maturation of 18S rRNA as well as the fitting of late ribosomal proteins into their mature position. Good Vibrations: Structural Remodeling of Maturing Yeast Pre-40S Ribosomal Particles Followed by Cryo-Electron Microscopy.,Shayan R, Rinaldi D, Larburu N, Plassart L, Balor S, Bouyssie D, Lebaron S, Marcoux J, Gleizes PE, Plisson-Chastang C Molecules. 2020 Mar 3;25(5). pii: molecules25051125. doi:, 10.3390/molecules25051125. PMID:32138239 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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