6swe | pdb_00006swe

IC2 head of cryo-EM structure of a full archaeal ribosomal translation initiation complex devoid of aIF1 in P. abyssi

Loading... Status: waiting for Mol* initialization Structural highlights 6swe is a 10 chain structure with sequence from Pyrococcus abyssi GE5. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.1Å Ligands: 4AC, 5MC, B8H, MG, OMC, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RS27A_PYRAB Publication Abstract from PubMed Archaeal translation initiation occurs within a macromolecular complex containing the small ribosomal subunit (30S) bound to mRNA, initiation factors aIF1, aIF1A and the ternary complex aIF2:GDPNP:Met-tRNAi(Met). Here, we determine the cryo-EM structure of a 30S:mRNA:aIF1A:aIF2:GTP:Met-tRNAi(Met) complex from Pyrococcus abyssi at 3.2 A resolution. It highlights archaeal features in ribosomal proteins and rRNA modifications. We find an aS21 protein, at the location of eS21 in eukaryotic ribosomes. Moreover, we identify an N-terminal extension of archaeal eL41 contacting the P site. We characterize 34 N(4)-acetylcytidines distributed throughout 16S rRNA, likely contributing to hyperthermostability. Without aIF1, the 30S head is stabilized and initiator tRNA is tightly bound to the P site. A network of interactions involving tRNA, mRNA, rRNA modified nucleotides and C-terminal tails of uS9, uS13 and uS19 is observed. Universal features and domain-specific idiosyncrasies of translation initiation are discussed in light of ribosomal structures from representatives of each domain of life. Cryo-EM study of an archaeal 30S initiation complex gives insights into evolution of translation initiation.,Coureux PD, Lazennec-Schurdevin C, Bourcier S, Mechulam Y, Schmitt E Commun Biol. 2020 Feb 6;3(1):58. doi: 10.1038/s42003-020-0780-0. PMID:32029867 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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