Figure 5.

(A) Effects of inducing the expression of ywaC gene on ribosome formation in RIK1066 cells. Growth of RIK1066 cells, IPTG treatment, and harvesting of cells were carried out exactly as described in the legend of Figure 4. Crude cell extracts were prepared from the harvested cells. Each cell extract was then sedimented through a 10–40% sucrose gradient as described in the Section Experimental procedures and the obtained sedimentation profiles are shown in this panel. The arrow indicates the additional peak. (B and C) Electron micrographs of the fractions corresponding to (B) 70S peak and (C) additional peak. RIK1066 cells were grown in LB medium at 37°C with shaking, IPTG was added at OD₆₀₀ = 0.2 and cells were harvested 60 min after the addition of IPTG. The peak fractions corresponding to 70S and additional peak were separately pooled and each fraction was further purified as described in the Section Experimental procedures.