Figure 2.

The FtsZ cleavage by protealysin in bacteria. (A). Growth curves of S. proteamaculans variants. Values are expressed as a mean of three repetitions ± S.D. (error bars). A difference was considered significant at the * p < 0.05 level. (B). Western blot detection of the expression of pln and m4in genes in S. proteamaculans. M—marker containing purified mature protealysin (Pln), protealysin precursor (proPln), and emfourin (M4in). WT, ∆(pln-m4in) and ∆m4in lanes were loaded with samples prepared from equal amounts of bacterial biomass. (C). Cleavage of actin by extracts of S. proteamaculans variants at 68 h of growth. (D). The number of FtsZ (estimated by Western blotting) in the same number of bacteria (determined by OD₆₀₀) at 16 h of growth. Values are expressed as mean of three repetitions ± S.D. (error bars). A difference was considered significant at the * p < 0.05 level. The insert shows a representative blot. An analysis of three technical replicates is presented. WT—wild-type S. proteamaculans; ∆(pln-m4in)—mutant S. proteamaculans with in-frame deletion of both genes of the protealysin operon; ∆m4in—mutant S. proteamaculans with in-frame deletion of emfourin gene. (E). The number of bacteria (CFU) in the bacterial suspensions at 20 and 47 h of growth normalized to the OD600 is shown in the insert.