Figure 2.

(A) Binding of N-Ac-Tyr-tRNA_Biot^Tyr to the large ribosomal subunit in the fragment reaction conditions. The amount of bound tRNA was estimated by nitrocellulose filter binding. Open circles represent binding in the absence of sparsomycin; solid circles show binding in the presence of 0.1 mM sparsomycin. (B) Trapping of the complex of large ribosomal subunits with N-acetyl-aminoacyl-tRNA on the avidin resin. ³²P-labeled 50S subunits were incubated with nonbiotinylated N-Ac-Tyr-tRNA, N-Ac-Tyr-tRNA_Biot, or N-Ac-Tyr-tRNA_Biot in the presence of sparsomycin and passed through the avidin resin, and, after washing, the captured material was eluted and counted.