
aIF1 is localized on the 30S ribosomal subunit. (A) Sedimentation profile (10%–30% sucrose gradient) of a S. solfataricus cell lysate, determined by A260 measurement in the absence of added mRNA. (B) Sedimentation profile (10%–30% sucrose gradient) of a S. solfataricus cell lysate programmed with 104 mRNA upon treatment with formaldehyde. The top and the bottom of the gradient are indicated. The gradients were fractionated and the fractions were probed for the presence of aIF1 with polyclonal antibodies raised against recombinant S. solfataricus aIF1 as described in Materials and Methods. The corresponding Western blots are shown below the sedimentation profiles.










