Fig. 1.

SlmA is an FtsZ polymerization antagonist. (A) FtsZ polymerization assays. Purified FtsZ (5 μM) was incubated in polymerization buffer (50 mM PIPES, pH 6.7, 10 mM MgCl₂, 200 mM KCl) at room temperature for 20 min with or without SlmA(WT) or SlmA variants (5 μM) as indicated. GTP (5 mM) was then added and FtsZ polymers were sedimented by ultracentrifugation. Proteins found in the resulting pellet (P) and supernatant (S) fractions were separated on an SDS-polyacrylamide gel and visualized by Coomassie brilliant blue staining. (B) NO defect of slmA missense alleles. TB57 [P_ara::minCDE] cells and its derivatives with the indicated slmA allele were grown overnight in M9-arabinose medium. The resulting cultures were serially diluted in LB (1% NaCl), 5 μL of each dilution was spotted on LB (1% NaCl) agar lacking arabinose, and the plate was incubated at 30 °C overnight. (C–E) Localization of SlmA variants. Cells of HC246 [ΔslmA] with the integrated expression constructs (attHKTB99) [P_lac::gfp-slmA] (C), (attHKHC482) [P_lac::gfp-slmA(R73D)] (D), or (attHKHC505) [P_lac::gfp-slmA(T33A)] (E) were grown to an OD₆₀₀ of 0.5 in LB with 250 μM IPTG and visualized using GFP (C1, D1, and E1) and DIC (C2, D2, and E2) optics.