Figure 5.

Effect of puromycin/high salt treatment on the amount of membrane-bound ribosomes in Ffh depleted and nondepleted cells. Extracts prepared from E. coli WAM113 grown with or without arabinose were incubated with or without puromycin (as indicated), and the ultracentrifuged pellets were resuspended and incubated in ribosome release buffer containing various KOAc concentrations. After flotation, identical aliquots from the interface fractions (containing membrane-bound ribosomes) were subjected to Western blotting with antibodies against the ribosomal proteins L9 and S13, as well as with anti-SecY antibodies.