6eml

Structural highlights

Function

[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.^{[1] [2]} [RS31_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: Component of the ribosome, a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell. The small ribosomal subunit (SSU) binds messenger RNAs (mRNAs) and translates the encoded message by selecting cognate aminoacyl-transfer RNA (tRNA) molecules. The large subunit (LSU) contains the ribosomal catalytic site termed the peptidyl transferase center (PTC), which catalyzes the formation of peptide bonds, thereby polymerizing the amino acids delivered by tRNAs into a polypeptide chain. The nascent polypeptides leave the ribosome through a tunnel in the LSU and interact with protein factors that function in enzymatic processing, targeting, and the membrane insertion of nascent chains at the exit of the ribosomal tunnel.^[3] [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] [RS7A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.^[4] [RS14A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.^[5] [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.^{[6] [7] [8]} [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.^[9] [RS6A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.^[10] [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). [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.^{[11] [12] [13] [14]} [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.^{[15] [16]} [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.^[17] [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.^{[18] [19]} [RS9A_YEAST] Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly.^[20] [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.^{[21] [22] [23] [24] [25]} [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.^[26]

See Also

• Ribosome 3D structures
• Ribosome biogenesis protein

References

1. ↑ Schafer T, Strauss D, Petfalski E, Tollervey D, Hurt E. The path from nucleolar 90S to cytoplasmic 40S pre-ribosomes. EMBO J. 2003 Mar 17;22(6):1370-80. PMID:12628929 doi:http://dx.doi.org/10.1093/emboj/cdg121
2. ↑ Leger-Silvestre I, Caffrey JM, Dawaliby R, Alvarez-Arias DA, Gas N, Bertolone SJ, Gleizes PE, Ellis SR. Specific Role for Yeast Homologs of the Diamond Blackfan Anemia-associated Rps19 Protein in Ribosome Synthesis. J Biol Chem. 2005 Nov 18;280(46):38177-85. Epub 2005 Sep 12. PMID:16159874 doi:http://dx.doi.org/10.1074/jbc.M506916200
3. ↑ Ben-Shem A, Garreau de Loubresse N, Melnikov S, Jenner L, Yusupova G, Yusupov M. The structure of the eukaryotic ribosome at 3.0 A resolution. Science. 2011 Dec 16;334(6062):1524-9. Epub 2011 Nov 17. PMID:22096102 doi:10.1126/science.1212642
4. ↑ Bernstein KA, Gallagher JE, Mitchell BM, Granneman S, Baserga SJ. The small-subunit processome is a ribosome assembly intermediate. Eukaryot Cell. 2004 Dec;3(6):1619-26. PMID:15590835 doi:http://dx.doi.org/10.1128/EC.3.6.1619-1626.2004
5. ↑ Bernstein KA, Gallagher JE, Mitchell BM, Granneman S, Baserga SJ. The small-subunit processome is a ribosome assembly intermediate. Eukaryot Cell. 2004 Dec;3(6):1619-26. PMID:15590835 doi:http://dx.doi.org/10.1128/EC.3.6.1619-1626.2004
6. ↑ Tone Y, Toh-E A. Nob1p is required for biogenesis of the 26S proteasome and degraded upon its maturation in Saccharomyces cerevisiae. Genes Dev. 2002 Dec 15;16(24):3142-57. PMID:12502737 doi:http://dx.doi.org/10.1101/gad.1025602
7. ↑ Senapin S, Clark-Walker GD, Chen XJ, Seraphin B, Daugeron MC. RRP20, a component of the 90S preribosome, is required for pre-18S rRNA processing in Saccharomyces cerevisiae. Nucleic Acids Res. 2003 May 15;31(10):2524-33. PMID:12736301
8. ↑ Vanrobays E, Gelugne JP, Caizergues-Ferrer M, Lafontaine DL. Dim2p, a KH-domain protein required for small ribosomal subunit synthesis. RNA. 2004 Apr;10(4):645-56. PMID:15037774
9. ↑ Tabb-Massey A, Caffrey JM, Logsden P, Taylor S, Trent JO, Ellis SR. Ribosomal proteins Rps0 and Rps21 of Saccharomyces cerevisiae have overlapping functions in the maturation of the 3' end of 18S rRNA. Nucleic Acids Res. 2003 Dec 1;31(23):6798-805. PMID:14627813
10. ↑ Bernstein KA, Gallagher JE, Mitchell BM, Granneman S, Baserga SJ. The small-subunit processome is a ribosome assembly intermediate. Eukaryot Cell. 2004 Dec;3(6):1619-26. PMID:15590835 doi:http://dx.doi.org/10.1128/EC.3.6.1619-1626.2004
11. ↑ Gelperin D, Horton L, Beckman J, Hensold J, Lemmon SK. Bms1p, a novel GTP-binding protein, and the related Tsr1p are required for distinct steps of 40S ribosome biogenesis in yeast. RNA. 2001 Sep;7(9):1268-83. PMID:11565749
12. ↑ Schafer T, Strauss D, Petfalski E, Tollervey D, Hurt E. The path from nucleolar 90S to cytoplasmic 40S pre-ribosomes. EMBO J. 2003 Mar 17;22(6):1370-80. PMID:12628929 doi:http://dx.doi.org/10.1093/emboj/cdg121
13. ↑ Leger-Silvestre I, Milkereit P, Ferreira-Cerca S, Saveanu C, Rousselle JC, Choesmel V, Guinefoleau C, Gas N, Gleizes PE. The ribosomal protein Rps15p is required for nuclear exit of the 40S subunit precursors in yeast. EMBO J. 2004 Jun 16;23(12):2336-47. Epub 2004 May 27. PMID:15167894 doi:http://dx.doi.org/10.1038/sj.emboj.7600252
14. ↑ Leger-Silvestre I, Caffrey JM, Dawaliby R, Alvarez-Arias DA, Gas N, Bertolone SJ, Gleizes PE, Ellis SR. Specific Role for Yeast Homologs of the Diamond Blackfan Anemia-associated Rps19 Protein in Ribosome Synthesis. J Biol Chem. 2005 Nov 18;280(46):38177-85. Epub 2005 Sep 12. PMID:16159874 doi:http://dx.doi.org/10.1074/jbc.M506916200
15. ↑ Ford CL, Randal-Whitis L, Ellis SR. Yeast proteins related to the p40/laminin receptor precursor are required for 20S ribosomal RNA processing and the maturation of 40S ribosomal subunits. Cancer Res. 1999 Feb 1;59(3):704-10. PMID:9973221
16. ↑ Tabb-Massey A, Caffrey JM, Logsden P, Taylor S, Trent JO, Ellis SR. Ribosomal proteins Rps0 and Rps21 of Saccharomyces cerevisiae have overlapping functions in the maturation of the 3' end of 18S rRNA. Nucleic Acids Res. 2003 Dec 1;31(23):6798-805. PMID:14627813
17. ↑ Bernstein KA, Gallagher JE, Mitchell BM, Granneman S, Baserga SJ. The small-subunit processome is a ribosome assembly intermediate. Eukaryot Cell. 2004 Dec;3(6):1619-26. PMID:15590835 doi:http://dx.doi.org/10.1128/EC.3.6.1619-1626.2004
18. ↑ Leger-Silvestre I, Caffrey JM, Dawaliby R, Alvarez-Arias DA, Gas N, Bertolone SJ, Gleizes PE, Ellis SR. Specific Role for Yeast Homologs of the Diamond Blackfan Anemia-associated Rps19 Protein in Ribosome Synthesis. J Biol Chem. 2005 Nov 18;280(46):38177-85. Epub 2005 Sep 12. PMID:16159874 doi:http://dx.doi.org/10.1074/jbc.M506916200
19. ↑ Gregory LA, Aguissa-Toure AH, Pinaud N, Legrand P, Gleizes PE, Fribourg S. Molecular basis of Diamond-Blackfan anemia: structure and function analysis of RPS19. Nucleic Acids Res. 2007;35(17):5913-21. Epub 2007 Aug 28. PMID:17726054 doi:10.1093/nar/gkm626
20. ↑ Bernstein KA, Gallagher JE, Mitchell BM, Granneman S, Baserga SJ. The small-subunit processome is a ribosome assembly intermediate. Eukaryot Cell. 2004 Dec;3(6):1619-26. PMID:15590835 doi:http://dx.doi.org/10.1128/EC.3.6.1619-1626.2004
21. ↑ Vanrobays E, Gelugne JP, Gleizes PE, Caizergues-Ferrer M. Late cytoplasmic maturation of the small ribosomal subunit requires RIO proteins in Saccharomyces cerevisiae. Mol Cell Biol. 2003 Mar;23(6):2083-95. PMID:12612080
22. ↑ Schafer T, Strauss D, Petfalski E, Tollervey D, Hurt E. The path from nucleolar 90S to cytoplasmic 40S pre-ribosomes. EMBO J. 2003 Mar 17;22(6):1370-80. PMID:12628929 doi:http://dx.doi.org/10.1093/emboj/cdg121
23. ↑ Geerlings TH, Faber AW, Bister MD, Vos JC, Raue HA. Rio2p, an evolutionarily conserved, low abundant protein kinase essential for processing of 20 S Pre-rRNA in Saccharomyces cerevisiae. J Biol Chem. 2003 Jun 20;278(25):22537-45. doi: 10.1074/jbc.M300759200. Epub 2003, Apr 10. PMID:12690111 doi:http://dx.doi.org/10.1074/jbc.M300759200
24. ↑ Leger-Silvestre I, Milkereit P, Ferreira-Cerca S, Saveanu C, Rousselle JC, Choesmel V, Guinefoleau C, Gas N, Gleizes PE. The ribosomal protein Rps15p is required for nuclear exit of the 40S subunit precursors in yeast. EMBO J. 2004 Jun 16;23(12):2336-47. Epub 2004 May 27. PMID:15167894 doi:http://dx.doi.org/10.1038/sj.emboj.7600252
25. ↑ Leger-Silvestre I, Caffrey JM, Dawaliby R, Alvarez-Arias DA, Gas N, Bertolone SJ, Gleizes PE, Ellis SR. Specific Role for Yeast Homologs of the Diamond Blackfan Anemia-associated Rps19 Protein in Ribosome Synthesis. J Biol Chem. 2005 Nov 18;280(46):38177-85. Epub 2005 Sep 12. PMID:16159874 doi:http://dx.doi.org/10.1074/jbc.M506916200
26. ↑ Leger-Silvestre I, Milkereit P, Ferreira-Cerca S, Saveanu C, Rousselle JC, Choesmel V, Guinefoleau C, Gas N, Gleizes PE. The ribosomal protein Rps15p is required for nuclear exit of the 40S subunit precursors in yeast. EMBO J. 2004 Jun 16;23(12):2336-47. Epub 2004 May 27. PMID:15167894 doi:http://dx.doi.org/10.1038/sj.emboj.7600252
27. ↑ Heuer A, Thomson E, Schmidt C, Berninghausen O, Becker T, Hurt E, Beckmann R. Cryo-EM structure of a late pre-40S ribosomal subunit from Saccharomyces cerevisiae. Elife. 2017 Nov 20;6. doi: 10.7554/eLife.30189. PMID:29155690 doi:http://dx.doi.org/10.7554/eLife.30189