Smc transcription and SMC levels during different phases of growth. A) Samples 1 to 4 were taken at the time points indicated in the growth curve (note that an OD of 0.5 is in the middle of exponential growth). B) Primer extension analysis of transcripts from growth phases shown in (A), arrowheads indicate the two start bases. C) Organization of the smc region. The two start bases are shown in the black box. The promoter region as derived from primer extension analysis lies within the rncS gene as indicated, and is highlighted in the dashed boxes in the sequence. The start of the smc gene is boxed, and the position of the primer used is underlined. RncS and smc genes are shown in italics. D) Western blot analysis of SMC during growth phases 1 to 4 (lanes 1, 2, 3, and 4). Cells from phases 1 and 2 were incubated after addition of chloramphenicol (Cm) as indicated by the arrows for 1, 2 or 4 hours (1 h, 2 h or 4 h). E) Western blot of CspB during growth phase 1, and 1, 2 or 4 hours after addition of Cm.