3izp | pdb_00003izp

Conformation of EF-G during translocation

Loading... Status: waiting for Mol* initialization Structural highlights 3izp is a 1 chain structure with sequence from Thermus thermophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function EFG_THETH Catalyzes the GTP-dependent ribosomal translocation step during translation elongation. During this step, the ribosome changes from the pre-translocational (PRE) to the post-translocational (POST) state as the newly formed A-site-bound peptidyl-tRNA and P-site-bound deacylated tRNA move to the P and E sites, respectively. Catalyzes the coordinated movement of the two tRNA molecules, the mRNA and conformational changes in the ribosome. Publication Abstract from PubMed Elongation factor G (EF-G) plays a crucial role in two stages of mRNA-(tRNA)(2) translocation. First, EF-G*GTP enters the pre-translocational ribosome in its intersubunit-rotated state, with tRNAs in their hybrid (P/E and A/P) positions. Second, a conformational change in EF-G's Domain IV induced by GTP hydrolysis disengages the mRNA-anticodon stem-loops of the tRNAs from the decoding center to advance relative to the small subunit when the ribosome undergoes a backward inter-subunit rotation. These events take place as EF-G undergoes a series of large conformational changes as visualized by cryo-EM and X-ray studies. The number and variety of these structures leave open many questions on how these different configurations form during the dynamic translocation process. To understand the molecular mechanism of translocation, we examined the molecular motions of EF-G in solution by means of molecular dynamics simulations. Our results show: (1) rotations of the super-domain formed by Domains III-V with respect to the super-domain formed by I-II, and rotations of Domain IV with respect to Domain III; (2) flexible conformations of both 503- and 575-loops; (3) large conformational variability in the bound form caused by the interaction between Domain V and the GTPase-associated center; (4) after GTP hydrolysis, the Switch I region seems to be instrumental for effecting the conformational change at the end of Domain IV implicated in the disengagement of the codon-anticodon helix from the decoding center. Proteins 2011; (c) 2011 Wiley-Liss, Inc. Molecular dynamics of EF-G during translocation.,Li W, Trabuco LG, Schulten K, Frank J Proteins. 2011 Jan 4. doi: 10.1002/prot.22976. PMID:21365677 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Elongation factor 3D structures

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