EMD-3581

Single-particle
5.6 Å
EMD-3581 Deposition: 26/01/2017
Map released: 11/10/2017
Last modified: 15/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-3581

Structure of 70S ribosome from Lactococcus lactis

EMD-3581

Single-particle
5.6 Å
EMD-3581 Deposition: 26/01/2017
Map released: 11/10/2017
Last modified: 15/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Lactococcus lactis subsp. cremoris (strain MG1363)
Sample: 70S ribosome
Fitted models: 5myj (Avg. Q-score: 0.248)

Deposition Authors: Franken LE , Oostergetel GT
A general mechanism of ribosome dimerization revealed by single-particle cryo-electron microscopy.
Franken LE , Oostergetel GT , Pijning T , Puri P, Arkhipova V , Boekema EJ, Poolman B, Guskov A
(2017) Nat Commun , 8 , 722 - 722
PUBMED: 28959045
DOI: doi:10.1038/s41467-017-00718-x
ISSN: 2041-1723
Abstract:
Bacteria downregulate their ribosomal activity through dimerization of 70S ribosomes, yielding inactive 100S complexes. In Escherichia coli, dimerization is mediated by the hibernation promotion factor (HPF) and ribosome modulation factor. Here we report the cryo-electron microscopy study on 100S ribosomes from Lactococcus lactis and a dimerization mechanism involving a single protein: HPFlong. The N-terminal domain of HPFlong binds at the same site as HPF in Escherichia coli 100S ribosomes. Contrary to ribosome modulation factor, the C-terminal domain of HPFlong binds exactly at the dimer interface. Furthermore, ribosomes from Lactococcus lactis do not undergo conformational changes in the 30S head domains upon binding of HPFlong, and the Shine-Dalgarno sequence and mRNA entrance tunnel remain accessible. Ribosome activity is blocked by HPFlong due to the inhibition of mRNA recognition by the platform binding center. Phylogenetic analysis of HPF proteins suggests that HPFlong-mediated dimerization is a widespread mechanism of ribosome hibernation in bacteria.When bacteria enter the stationary growth phase, protein translation is suppressed via the dimerization of 70S ribosomes into inactive complexes. Here the authors provide a structural basis for how the dual domain hibernation promotion factor promotes ribosome dimerization and hibernation in bacteria.