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Title: Crystal Structures of EF-G-Ribosome Complexes Trapped in Intermediate States of Translocation

Translocation of messenger and transfer RNA (mRNA and tRNA) through the ribosome is a crucial step in protein synthesis, whose mechanism is not yet understood. The crystal structures of three Thermus ribosome-tRNA-mRNA–EF-G complexes trapped with β,γ-imidoguanosine 5'-triphosphate (GDPNP) or fusidic acid reveal conformational changes occurring during intermediate states of translocation, including large-scale rotation of the 30S subunit head and body. In all complexes, the tRNA acceptor ends occupy the 50S subunit E site, while their anticodon stem loops move with the head of the 30S subunit to positions between the P and E sites, forming chimeric intermediate states. Two universally conserved bases of 16S ribosomal RNA that intercalate between bases of the mRNA may act as “pawls” of a translocational ratchet. These findings provide new insights into the molecular mechanism of ribosomal translocation.
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  1. UCSC
Publication Date:
OSTI Identifier:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Science; Journal Volume: 340; Journal Issue: 06, 2013
Research Org:
Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
Sponsoring Org:
Country of Publication:
United States