| Structural highlights
Function
[RL5_YEAST] Binds 5S RNA and is required for 60S subunit assembly. [RL37A_YEAST] Binds to the 23S rRNA (By similarity). [IF5A1_YEAST] mRNA-binding protein involved in translation elongation. Has an important function at the level of mRNA turnover, probably acting downstream of decapping. Involved in actin dynamics and cell cycle progression, mRNA decay and probably in a pathway involved in stress response and maintenance of cell wall integrity. Essential for polarized growth, a process necessary for G1/S transition. May mediate large range of effects of the polyamine spermidine in the cell.[1] [2] [3] [4] [5] [6] [7] [8] [9] [RL11A_YEAST] Binds to 5S ribosomal RNA. [RL25_YEAST] This protein binds to a specific region on the 26S rRNA. [RL401_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).[10] 60S ribosomal protein L40: component of the 60S subunit of the ribosome. Ribosomal protein L40 is essential for translation of a subset of cellular transcripts, including stress response transcripts, such as DDR2.[11] [RL4A_YEAST] Participates in the regulation of the accumulation of its own mRNA.[12]
Publication Abstract from PubMed
During protein synthesis, ribosomes become stalled on polyproline-containing sequences, unless they are rescued in archaea and eukaryotes by the initiation factor 5A (a/eIF-5A) and in bacteria by the homologous protein EF-P. While a structure of EF-P bound to the 70S ribosome exists, structural insight into eIF-5A on the 80S ribosome has been lacking. Here we present a cryo-electron microscopy reconstruction of eIF-5A bound to the yeast 80S ribosome at 3.9 A resolution. The structure reveals that the unique and functionally essential post-translational hypusine modification reaches toward the peptidyltransferase center of the ribosome, where the hypusine moiety contacts A76 of the CCA-end of the P-site tRNA. These findings would support a model whereby eIF-5A stimulates peptide bond formation on polyproline-stalled ribosomes by stabilizing and orienting the CCA-end of the P-tRNA, rather than by directly contributing to the catalysis.
Structure of the hypusinylated eukaryotic translation factor eIF-5A bound to the ribosome.,Schmidt C, Becker T, Heuer A, Braunger K, Shanmuganathan V, Pech M, Berninghausen O, Wilson DN, Beckmann R Nucleic Acids Res. 2015 Dec 28. pii: gkv1517. PMID:26715760[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Lee YB, Joe YA, Wolff EC, Dimitriadis EK, Park MH. Complex formation between deoxyhypusine synthase and its protein substrate, the eukaryotic translation initiation factor 5A (eIF5A) precursor. Biochem J. 1999 May 15;340 ( Pt 1):273-81. PMID:10229683
- ↑ Zanelli CF, Valentini SR. Pkc1 acts through Zds1 and Gic1 to suppress growth and cell polarity defects of a yeast eIF5A mutant. Genetics. 2005 Dec;171(4):1571-81. Epub 2005 Sep 12. PMID:16157662 doi:http://dx.doi.org/genetics.105.048082
- ↑ Chatterjee I, Gross SR, Kinzy TG, Chen KY. Rapid depletion of mutant eukaryotic initiation factor 5A at restrictive temperature reveals connections to actin cytoskeleton and cell cycle progression. Mol Genet Genomics. 2006 Mar;275(3):264-76. Epub 2006 Jan 12. PMID:16408210 doi:http://dx.doi.org/10.1007/s00438-005-0086-4
- ↑ Zanelli CF, Maragno AL, Gregio AP, Komili S, Pandolfi JR, Mestriner CA, Lustri WR, Valentini SR. eIF5A binds to translational machinery components and affects translation in yeast. Biochem Biophys Res Commun. 2006 Oct 6;348(4):1358-66. Epub 2006 Aug 7. PMID:16914118 doi:http://dx.doi.org/10.1016/j.bbrc.2006.07.195
- ↑ Gregio AP, Cano VP, Avaca JS, Valentini SR, Zanelli CF. eIF5A has a function in the elongation step of translation in yeast. Biochem Biophys Res Commun. 2009 Mar 20;380(4):785-90. Epub 2009 Jan 29. PMID:19338753 doi:http://dx.doi.org/S0006-291X(09)00203-4
- ↑ Saini P, Eyler DE, Green R, Dever TE. Hypusine-containing protein eIF5A promotes translation elongation. Nature. 2009 May 7;459(7243):118-21. PMID:19424157 doi:http://dx.doi.org/nature08034
- ↑ Benne R, Hershey JW. The mechanism of action of protein synthesis initiation factors from rabbit reticulocytes. J Biol Chem. 1978 May 10;253(9):3078-87. PMID:641056
- ↑ Kang HA, Hershey JW. Effect of initiation factor eIF-5A depletion on protein synthesis and proliferation of Saccharomyces cerevisiae. J Biol Chem. 1994 Feb 11;269(6):3934-40. PMID:8307948
- ↑ Zuk D, Jacobson A. A single amino acid substitution in yeast eIF-5A results in mRNA stabilization. EMBO J. 1998 May 15;17(10):2914-25. PMID:9582285 doi:http://dx.doi.org/10.1093/emboj/17.10.2914
- ↑ Lee AS, Burdeinick-Kerr R, Whelan SP. A ribosome-specialized translation initiation pathway is required for cap-dependent translation of vesicular stomatitis virus mRNAs. Proc Natl Acad Sci U S A. 2013 Jan 2;110(1):324-9. doi: 10.1073/pnas.1216454109. , Epub 2012 Nov 19. PMID:23169626 doi:http://dx.doi.org/10.1073/pnas.1216454109
- ↑ Lee AS, Burdeinick-Kerr R, Whelan SP. A ribosome-specialized translation initiation pathway is required for cap-dependent translation of vesicular stomatitis virus mRNAs. Proc Natl Acad Sci U S A. 2013 Jan 2;110(1):324-9. doi: 10.1073/pnas.1216454109. , Epub 2012 Nov 19. PMID:23169626 doi:http://dx.doi.org/10.1073/pnas.1216454109
- ↑ Presutti C, Ciafre SA, Bozzoni I. The ribosomal protein L2 in S. cerevisiae controls the level of accumulation of its own mRNA. EMBO J. 1991 Aug;10(8):2215-21. PMID:2065661
- ↑ Schmidt C, Becker T, Heuer A, Braunger K, Shanmuganathan V, Pech M, Berninghausen O, Wilson DN, Beckmann R. Structure of the hypusinylated eukaryotic translation factor eIF-5A bound to the ribosome. Nucleic Acids Res. 2015 Dec 28. pii: gkv1517. PMID:26715760 doi:http://dx.doi.org/10.1093/nar/gkv1517
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