6ucq

Publication Abstract from PubMed

The bacterial ribosome is recycled into subunits by two conserved proteins, elongation factor G (EF-G) and the ribosome recycling factor (RRF). The molecular basis for ribosome recycling by RRF and EF-G remains unclear. Here, we report the crystal structure of a posttermination Thermus thermophilus 70S ribosome complexed with EF-G, RRF and two transfer RNAs at a resolution of 3.5 A. The deacylated tRNA in the peptidyl (P) site moves into a previously unsuspected state of binding (peptidyl/recycling, p/R) that is analogous to that seen during initiation. The terminal end of the p/R-tRNA forms nonfavorable contacts with the 50S subunit while RRF wedges next to central inter-subunit bridges, illuminating the active roles of tRNA and RRF in dissociation of ribosomal subunits. The structure uncovers a missing snapshot of tRNA as it transits between the P and exit (E) sites, providing insights into the mechanisms of ribosome recycling and tRNA translocation.

Structural Basis for Ribosome Recycling by RRF and tRNA.,Zhou D, Tanzawa T, Lin J, Gagnon MG Nat Struct Mol Biol. 2019 Dec 23. pii: 10.1038/s41594-019-0350-7. doi:, 10.1038/s41594-019-0350-7. PMID:31873307^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.