Binding of FtsY to ribosome nascent chains requires the presence of signal recognition particles (SRP) and guanosine 5'(β,-γ imido) triphosphate (GMP)-PNP. MtlA189 RNCs were in vitro synthesized in the presence of purified SRP and in vitro synthesized, purified FtsY. When indicated puromycin or GMP-PNP were added. Ribosome-nascent chains (RNCs) were subsequently separated by centrifugation through a sucrose cushion into pellet fraction (P) and supernatant (S), which were analysed on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Both panels of the figure correspond to the same gel but were separated due to the large size-difference between FtsY and the RNCs. The radioactive material was quantified using a phosphor imager and the Imagequant software. Three independent experiments were performed.
Mircheva et al. BMC Biology 2009 7:76 doi:10.1186/1741-7007-7-76