Figure 3.

Quantitative analysis of stalk dimers bound to P0 carrying mutations in helices I and II in the 50S particle. The 50S core particles (30 pmol) were mixed with excess amounts of the P0–P1–P2 complexes (90 pmol), which are composed of P1–[³²P]P2 dimers (840 cpm/pmol) and P0, and eL12 (90 pmol) (A). The hybrid 50S particles were also reconstituted using P0mutI (B), and P0mutII (C), instead of P0. The hybrid 50S samples were separated by sucrose gradient centrifugation, as described in ‘Materials and Methods’ section. The amount of P2 incorporated to the 50S core was estimated by radioactivity of P2 and the absorbance at 260 nm of the 50S core.