7y7g

Structure of the Bacterial Ribosome with human tRNA Tyr(GalQ34) and mRNA(UAU)

spinqualitylabelsall models 7y7g, resolution 2.34Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7y7g is a 10 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.34Å Ligands: 1MA, 1MG, 2MA, 2MG, 3AU, 3TD, 4D4, 4OC, 4SU, 56B, 5MC, 5MU, 6MZ, D2T, G7M, GAL, H2U, IAS, M2G, MA6, MEQ, MG, MS6, OMC, OMG, OMU, PSU, UR3, UY1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RS4_ECOLI One of two assembly initiator proteins for the 30S subunit, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit. With S5 and S12 plays an important role in translational accuracy; many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations). Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp. Protein S4 is also a translational repressor protein, it controls the translation of the alpha-operon (which codes for S13, S11, S4, RNA polymerase alpha subunit, and L17) by binding to its mRNA. Also functions as a rho-dependent antiterminator of rRNA transcription, increasing the synthesis of rRNA under conditions of excess protein, allowing a more rapid return to homeostasis. Binds directly to RNA polymerase. Publication Abstract from PubMed Transfer RNA (tRNA) modifications are critical for protein synthesis. Queuosine (Q), a 7-deaza-guanosine derivative, is present in tRNA anticodons. In vertebrate tRNAs for Tyr and Asp, Q is further glycosylated with galactose and mannose to generate galQ and manQ, respectively. However, biogenesis and physiological relevance of Q-glycosylation remain poorly understood. Here, we biochemically identified two RNA glycosylases, QTGAL and QTMAN, and successfully reconstituted Q-glycosylation of tRNAs using nucleotide diphosphate sugars. Ribosome profiling of knockout cells revealed that Q-glycosylation slowed down elongation at cognate codons, UAC and GAC (GAU), respectively. We also found that galactosylation of Q suppresses stop codon readthrough. Moreover, protein aggregates increased in cells lacking Q-glycosylation, indicating that Q-glycosylation contributes to proteostasis. Cryo-EM of human ribosome-tRNA complex revealed the molecular basis of codon recognition regulated by Q-glycosylations. Furthermore, zebrafish qtgal and qtman knockout lines displayed shortened body length, implying that Q-glycosylation is required for post-embryonic growth in vertebrates. Glycosylated queuosines in tRNAs optimize translational rate and post-embryonic growth.,Zhao X, Ma D, Ishiguro K, Saito H, Akichika S, Matsuzawa I, Mito M, Irie T, Ishibashi K, Wakabayashi K, Sakaguchi Y, Yokoyama T, Mishima Y, Shirouzu M, Iwasaki S, Suzuki T, Suzuki T Cell. 2023 Dec 7;186(25):5517-5535.e24. doi: 10.1016/j.cell.2023.10.026. Epub , 2023 Nov 21. PMID:37992713 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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