4v6l

Structural insights into cognate vs. near-cognate discrimination during decoding.Structural insights into cognate vs. near-cognate discrimination during decoding.

4v6l, resolution 13.20Å Show:Asymmetric Unit Biological Assembly Structural highlights 4v6l is a 10 chain structure with sequence from Escherichia coli K-12 and Escherichia coli O157:H7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 13.2Å Ligands: Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RS5_ECOLI With S4 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). Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body. The physical location of this protein suggests it may also play a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp. Publication Abstract from PubMed The structural basis of the tRNA selection process is investigated by cryo-electron microscopy of ribosomes programmed with UGA codons and incubated with ternary complex (TC) containing the near-cognate Trp-tRNA(Trp) in the presence of kirromycin. Going through more than 350 000 images and employing image classification procedures, we find approximately 8% in which the TC is bound to the ribosome. The reconstructed 3D map provides a means to characterize the arrangement of the near-cognate aa-tRNA with respect to elongation factor Tu (EF-Tu) and the ribosome, as well as the domain movements of the ribosome. One of the interesting findings is that near-cognate tRNA's acceptor stem region is flexible and CCA end becomes disordered. The data bring direct structural insights into the induced-fit mechanism of decoding by the ribosome, as the analysis of the interactions between small and large ribosomal subunit, aa-tRNA and EF-Tu and comparison with the cognate case (UGG codon) offers clues on how the conformational signals conveyed to the GTPase differ in the two cases. Structural insights into cognate versus near-cognate discrimination during decoding.,Agirrezabala X, Schreiner E, Trabuco LG, Lei J, Ortiz-Meoz RF, Schulten K, Green R, Frank J EMBO J. 2011 Mar 4. PMID:21378755 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Elongation factor 3D structures Ribosome 3D structures Transfer RNA (tRNA)