4v6w | pdb_00004v6w
Structure of the D. melanogaster 80S ribosome
Structural highlights
Function[RL3_DROME] The L3 protein is a component of the large subunit of cytoplasmic ribosomes. [RL371_DROME] Binds to the 23S rRNA (By similarity). [RSSA_DROME] 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. Required during oogenesis and imaginal development.[1] [RL5_DROME] This protein binds 5S RNA (By similarity). [RS6_DROME] May play an important role in controlling cell growth and proliferation through the selective translation of particular classes of mRNA. [RL7_DROME] Binds to G-rich structures in 28S rRNA and in mRNAs. Plays a regulatory role in the translation apparatus; inhibits cell-free translation of mRNAs (By similarity). [RS3A_DROME] Essential for oogenesis; required for late follicle cell development.[2] [RS21_DROME] May be an associated component of the ribosome rather than a core structural subunit. May act as a translation initiation factor. Has a role in regulation of cell proliferation in the hematopoietic organs and the imaginal disks of larva.[3] [EF2_DROME] Catalyzes the GTP-dependent ribosomal translocation step during translation elongation. During this step, the ribosome changes from the pre-translocational (PRE) to the post-translocational (POST) state as the newly formed A-site-bound peptidyl-tRNA and P-site-bound deacylated tRNA move to the P and E sites, respectively. Catalyzes the coordinated movement of the two tRNA molecules, the mRNA and conformational changes in the ribosome. [RS27A_DROME] 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-48-linked is involved in protein degradation via the proteasome. 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). Ribosomal protein S27a is a component of the 40S subunit of the ribosome. [RS2_DROME] Has a specific developmental role during oogenesis and a general role in protein synthesis as a component of the small ribosomal subunit.[4] [RL40_DROME] 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-48-linked is involved in protein degradation via the proteasome. 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). Ribosomal protein L40 is a component of the 60S subunit of the ribosome. [RL11_DROME] Binds to 5S ribosomal RNA (By similarity). [RS3_DROME] Has DNA repair activity directed towards the mutagenic lesions 8-oxoguanine and abasic sites in DNA. It can cleave DNA containing 8-oxoguanine residues efficiently. Also acts as an ap lyase, cleaving phosphodiester bonds via a beta,delta elimination reaction. [RS18_DROME] 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] Publication Abstract from PubMedProtein synthesis in all cells is carried out by macromolecular machines called ribosomes. Although the structures of prokaryotic, yeast and protist ribosomes have been determined, the more complex molecular architecture of metazoan 80S ribosomes has so far remained elusive. Here we present structures of Drosophila melanogaster and Homo sapiens 80S ribosomes in complex with the translation factor eEF2, E-site transfer RNA and Stm1-like proteins, based on high-resolution cryo-electron-microscopy density maps. These structures not only illustrate the co-evolution of metazoan-specific ribosomal RNA with ribosomal proteins but also reveal the presence of two additional structural layers in metazoan ribosomes, a well-ordered inner layer covered by a flexible RNA outer layer. The human and Drosophila ribosome structures will provide the basis for more detailed structural, biochemical and genetic experiments. Structures of the human and Drosophila 80S ribosome.,Anger AM, Armache JP, Berninghausen O, Habeck M, Subklewe M, Wilson DN, Beckmann R Nature. 2013 May 2;497(7447):80-5. doi: 10.1038/nature12104. PMID:23636399[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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