SRP RNA binding activities of Af-SRP19 and Af-SRP54 proteins. Proteins separated by electrophoresis on 15% polyacrylamide gels and stained with Coomassie blue in the flowthrough (F) and high-salt eluate (E) of DEAE-columns (see Materials and Methods). Lane 1, 1 µg Af-SRP19 in absence of Af-SRP RNA; lane 2, 1 µg Af-SRP19 mixed with 10 µg Af-SRP RNA; lane 3, 3.8 µg Af-SRP54 in absence of Af-SRP RNA; lane 4, 3.8 µg Af-SRP54 added to 10 µg Af-SRP RNA; lane 5, 1 µg Af-SRP19 and 3.8 µg Af-SRP54 with 10 µg of Af-SRP RNA. Pre-stained high molecular weight markers (Gibco BRL) with sizes indicated in kDa in lane M.