Fig. 1.

The sedimentation coefficients of in vivo 50S assembly intermediates from WT and ΔrrmJ cells under different Mg²⁺ concentrations. (A) Ribosome profile of WT and rrmJ-deletion cells at 0.5 mM or 10.5 mM Mg²⁺. (B) Ribosome profile of ΔrrmJ cells at varying concentration of Mg²⁺. (C and D) Sedimentation analysis of purified ΔrrmJ 45S fractions (green box in A) and WT 50S fractions (blue box in A) with a buffer containing low (0.5 mM, black curves) or high level of Mg²⁺ (10.5 mM, red curves). The sedimentation coefficient of purified ΔrrmJ 45S particles increases to 50S under high Mg²⁺ concentration.