4v7a

E. coli 70S-fMetVal-tRNAVal post-translocation complex (post4)

Loading... Status: waiting for Mol* initialization Structural highlights 4v7a is a 10 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 9Å Ligands: 4SU, 5MU, 6MZ, 7MG, ACE, CM0, FME, NH2, PSU, VAL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RS12_ECOLI With S4 and S5 plays an important role in translational accuracy.[HAMAP-Rule:MF_00403_B] Interacts with and stabilizes bases of the 16S rRNA that are involved in tRNA selection in the A site and with the mRNA backbone. Located at the interface of the 30S and 50S subunits, it traverses the body of the 30S subunit contacting proteins on the other side and probably holding the rRNA structure together. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit (By similarity).[HAMAP-Rule:MF_00403_B] Cryo-EM studies suggest that S12 contacts the EF-Tu bound tRNA in the A-site during codon-recognition. This contact is most likely broken as the aminoacyl-tRNA moves into the peptidyl transferase center in the 50S subunit.[HAMAP-Rule:MF_00403_B] Publication Abstract from PubMed During protein synthesis, tRNAs move from the ribosome's aminoacyl to peptidyl to exit sites. Here we investigate conformational motions during spontaneous translocation, using molecular dynamics simulations of 13 intermediate-translocation-state models obtained by combining Escherichia coli ribosome crystal structures with cryo-EM data. Resolving fast transitions between states, we find that tRNA motions govern the transition rates within the pre- and post-translocation states. Intersubunit rotations and L1-stalk motion exhibit fast intrinsic submicrosecond dynamics. The L1 stalk drives the tRNA from the peptidyl site and links intersubunit rotation to translocation. Displacement of tRNAs is controlled by 'sliding' and 'stepping' mechanisms involving conserved L16, L5 and L1 residues, thus ensuring binding to the ribosome despite large-scale tRNA movement. Our results complement structural data with a time axis, intrinsic transition rates and molecular forces, revealing correlated functional motions inaccessible by other means. Energy barriers and driving forces in tRNA translocation through the ribosome.,Bock LV, Blau C, Schroder GF, Davydov II, Fischer N, Stark H, Rodnina MV, Vaiana AC, Grubmuller H Nat Struct Mol Biol. 2013 Nov 3. doi: 10.1038/nsmb.2690. PMID:24186064 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Transfer RNA (tRNA)

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