4wpo
From Proteopedia
Crystal structure of the Thermus thermophilus 70S ribosome in complex with elongation factor G in the pre-translocational state
Structural highlights
FunctionRL1_THET8 Directly binds to 23S rRNA. Forms what is known as the L1 stalk, which protrudes beyond the 70S ribosome surface. The stalk is preferentially stabilized in 70S versus 50S crystals. Interacts with the E site tRNA, blocking the exit path. This blockage implies that this section of the ribosome must be able to move to release the deacetylated tRNA.[HAMAP-Rule:MF_01318_B] Protein L1 is also a translational repressor protein, it controls the translation of the L11 operon by binding to its mRNA (By similarity).[HAMAP-Rule:MF_01318_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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