6n1d

X-ray Crystal complex showing Spontaneous Ribosomal Translocation of mRNA and tRNAs into a Chimeric Hybrid State

spinqualitylabelsall models 6n1d, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6n1d is a 20 chain structure with sequence from Thermus thermophilus and Thermus thermophilus HB27. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.2Å Ligands: 4SU, 5MU, 6MZ, CM0, G7M, MG, MIA, PSU, QUO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RL1_THET2 Binds directly to 23S rRNA. The L1 stalk is quite mobile in the ribosome, and is involved in E site tRNA release (By similarity). Protein L1 is also a translational repressor protein, it controls the translation of the L11 operon by binding to its mRNA (By similarity). Publication Abstract from PubMed The elongation factor G (EF-G)-catalyzed translocation of mRNA and tRNA through the ribosome is essential for vacating the ribosomal A site for the next incoming aminoacyl-tRNA, while precisely maintaining the translational reading frame. Here, the 3.2-A crystal structure of a ribosome translocation intermediate complex containing mRNA and two tRNAs, formed in the absence of EF-G or GTP, provides insight into the respective roles of EF-G and the ribosome in translocation. Unexpectedly, the head domain of the 30S subunit is rotated by 21 degrees , creating a ribosomal conformation closely resembling the two-tRNA chimeric hybrid state that was previously observed only in the presence of bound EF-G. The two tRNAs have moved spontaneously from their A/A and P/P binding states into ap/P and pe/E states, in which their anticodon loops are bound between the 30S body domain and its rotated head domain, while their acceptor ends have moved fully into the 50S P and E sites, respectively. Remarkably, the A-site tRNA translocates fully into the classical P-site position. Although the mRNA also undergoes movement, codon-anticodon interaction is disrupted in the absence of EF-G, resulting in slippage of the translational reading frame. We conclude that, although movement of both tRNAs and mRNA (along with rotation of the 30S head domain) can occur in the absence of EF-G and GTP, EF-G is essential for enforcing coupled movement of the tRNAs and their mRNA codons to maintain the reading frame. Spontaneous ribosomal translocation of mRNA and tRNAs into a chimeric hybrid state.,Zhou J, Lancaster L, Donohue JP, Noller HF Proc Natl Acad Sci U S A. 2019 Apr 1. pii: 1901310116. doi:, 10.1073/pnas.1901310116. PMID:30936299 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribosomal protein THX 3D structures Ribosome 3D structures

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