Visualizing Compaction of Polysomes in Bacteria. - Archive ouverte HAL Access content directly
Journal Articles Journal of Molecular Biology Year : 2013

Visualizing Compaction of Polysomes in Bacteria.


During protein synthesis, many translating ribosomes are bound together with an mRNA molecule to form polysomes (or polyribosomes). While the spatial organization of bacterial polysomes has been well studied in vitro, little is known about how they cluster when cellular conditions are highly constrained. To better understand this, we used electron tomography, template matching, and three-dimensional modeling to analyze the supramolecular network of ribosomes after induction of translational pauses. In Escherichia coli, we overexpressed an mRNA carrying a polyproline motif known to induce pausing during translation. When working with a strain lacking transfer-messenger RNA, the principle actor in the "trans-translation" rescuing system, the cells survived the hijacking of the translation machinery but this resulted in a sharp modification of the ribosomal network. The results of our experiments demonstrate that single ribosomes are replaced with large amounts of compacted polysomes. These polysomes are highly organized, principally forming hairpins and dimers of hairpins that stack together. We propose that these spatial arrangements help maintain translation efficiency when the rescue systems are absent or overwhelmed.
Fichier principal
Vignette du fichier
Cougot_et_al_JMB-Visualizing-compaction_revised2.pdf (8.73 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-00874756 , version 1 (18-10-2013)



Nicolas Cougot, Anne-Elisabeth Molza, Jeremy Delesques, Emmanuel Giudice, Annie Cavalier, et al.. Visualizing Compaction of Polysomes in Bacteria.. Journal of Molecular Biology, 2013, 426 (2), pp.377-388. ⟨10.1016/j.jmb.2013.09.035⟩. ⟨hal-00874756⟩
249 View
658 Download



Gmail Facebook Twitter LinkedIn More