Translation initiation complex formation in the crenarchaeon Sulfolobus solfataricus

aIF1 and aIF1A stimulate a/eIF2 binding to S. solfataricus 30S ribosomal subunits. (A) a/eIF2₅₆₅ binding to 30S ribosomal subunits (orange trace) and in the presence of 30S-bound aIF1A (green trace), aIF1 (blue trace), and aIF1/aIF1A (red trace), respectively. The chart shows the A₁, k_app1, A₂, k_app2, and k_av values determined by a two-exponential fitting as described in Materials and Methods. (B) The k_on values for a/eIF2₅₆₅ binding to 30S•aIF1•aIF1A complexes (▼) and to 30S subunits (■) were determined by titration of the respective k_app2 values obtained at different concentrations of a/eIF2₅₆₅. The chart shows the k_on, k_off, and K_d values determined as described in Materials and Methods.