BioProject

The factor RsfS is present in almost all bacteria and organelles. RsfS is important under conditions of nutrient downshifts leading to decreasing growth rates. More...

The factor RsfS is present in almost all bacteria and organelles. RsfS is important under conditions of nutrient downshifts leading to decreasing growth rates. A common feature of these conditions is a strong reduction of the translation capacity revealed by polysomal fraction decrease and a vast appearance of vacant 70S ribosomes, which might cause a devastating energy drain by stimulating the activity of GTPase proteins e.g. EF-G with idle ribosomes. Here we show that RsfS blocks association of free ribosomal subunits and induces dissociation exclusively of vacant ribosomes rather than of programmed ribosomes carrying tRNAs. As a consequence, RsfS reduces the abundance of the cellular translational apparatus, and the EF-G dependent burst of GTP cleavage in the presence of vacant 70S ribosomes as well as with 30S and 50S subunits is decreased. These observations hint to a regulatory role of RsfS by utilizing cellular resource in an economic way under conditions, where the amino acids are limited and energy has to be saved. Overall design: Ribo-seq of E. coli strain BW25113 and BW25113_ΔRsfS in M9 minimal medium. Less...