4wqu
From Proteopedia
Crystal structure of the Thermus thermophilus 70S ribosome in complex with elongation factor G trapped by the antibiotic dityromycin
Structural highlights
FunctionRL4_THET8 One of the primary rRNA binding proteins, this protein initially binds near the 5'-end of the 23S rRNA. It is important during the early stages of 50S assembly. It makes multiple contacts with different domains of the 23S rRNA in the assembled 50S subunit and ribosome (By similarity).[HAMAP-Rule:MF_01328_B] Forms part of the polypeptide exit tunnel (By similarity).[HAMAP-Rule:MF_01328_B] This protein can be incorporated into E.coli ribosomes in vivo, which resulted in decreased peptidyltransferase (Ptase) activity of the hybrid ribosomes. The hybrid 50S subunits associate less well with 30S subunits to form the ribosome.[HAMAP-Rule:MF_01328_B] Publication Abstract from PubMedThe universally conserved GTPase elongation factor G (EF-G) catalyzes the translocation of tRNA and mRNA on the ribosome after peptide bond formation. Despite numerous studies suggesting that EF-G undergoes extensive conformational rearrangements during translocation, high-resolution structures exist for essentially only one conformation of EF-G in complex with the ribosome. Here, we report four atomic-resolution crystal structures of EF-G bound to the ribosome programmed in the pre- and posttranslocational states and to the ribosome trapped by the antibiotic dityromycin. We observe a previously unseen conformation of EF-G in the pretranslocation complex, which is independently captured by dityromycin on the ribosome. Our structures provide insights into the conformational space that EF-G samples on the ribosome and reveal that tRNA translocation on the ribosome is facilitated by a structural transition of EF-G from a compact to an elongated conformation, which can be prevented by the antibiotic dityromycin. Conformational Changes of Elongation Factor G on the Ribosome during tRNA Translocation.,Lin J, Gagnon MG, Bulkley D, Steitz TA Cell. 2015 Jan 15;160(1-2):219-27. doi: 10.1016/j.cell.2014.11.049. PMID:25594181[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also
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