4v97

Crystal structure of the bacterial ribosome ram mutation G299A.

spinqualitylabelsall models 4v97, resolution 3.52Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4v97 is a 20 chain structure with sequence from Thermus thermophilus HB8. This structure supersedes the now removed PDB entries 4ej9, 4eja, 4ejb and 4ejc. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.516Å Ligands: MG, PAR, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RS2_THET8 Spans the head-body hinge region of the 30S subunit. Is loosely associated with the 30S subunit.[HAMAP-Rule:MF_00291_B] Publication Abstract from PubMed After four decades of research aimed at understanding tRNA selection on the ribosome, the mechanism by which ribosomal ambiguity (ram) mutations promote miscoding remains unclear. Here, we present two X-ray crystal structures of the Thermus thermophilus 70S ribosome containing 16S rRNA ram mutations, G347U and G299A. Each of these mutations causes miscoding in vivo and stimulates elongation factor thermo unstable (EF-Tu)-dependent GTP hydrolysis in vitro. Mutation G299A is located near the interface of ribosomal proteins S4 and S5 on the solvent side of the subunit, whereas G347U is located 77 A distant, at intersubunit bridge B8, close to where EF-Tu engages the ribosome. Despite these disparate locations, both mutations induce almost identical structural rearrangements that disrupt the B8 bridge-namely, the interaction of h8/h14 with L14 and L19. This conformation most closely resembles that seen upon EF-TuGTPaminoacyl-tRNA binding to the 70S ribosome. These data provide evidence that disruption and/or distortion of B8 is an important aspect of GTPase activation. We propose that, by destabilizing B8, G299A and G347U reduce the energetic cost of attaining the GTPase-activated state and thereby decrease the stringency of decoding. This previously unappreciated role for B8 in controlling the decoding process may hold relevance for many other ribosomal mutations known to influence translational fidelity. Reorganization of an intersubunit bridge induced by disparate 16S ribosomal ambiguity mutations mimics an EF-Tu-bound state.,Fagan CE, Dunkle JA, Maehigashi T, Dang MN, Devaraj A, Miles SJ, Qin D, Fredrick K, Dunham CM Proc Natl Acad Sci U S A. 2013 Apr 29. PMID:23630274 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribosomal protein THX 3D structures Ribosome 3D structures Transfer RNA (tRNA)

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