FIG 3.

Phenotype of SPOR-less DedD. (A to J) DIC images of live cells of strains BL40(iBL360) [ΔdamX ΔdedD(P_lac::gfp-dedD)] (A to E) and BL40(iBL345) [ΔdamX ΔdedD(P_lac::gfp-dedD^1–118)] (F to J). The cells were grown for ∼3 mass doublings to an OD₆₀₀ of 0.5 to 0.6 in M9-maltose with 0 μM (A and F), 10 μM (B and G), 50 μM (C and H), 100 μM (D and I), or 250 μM (E and J) IPTG. Bar, 4 μm. (K) Western analysis of full-length GFP-DedD and SPOR-less GFP-DedD^1–118. Nonchaining cells of strains BL38 [ΔdamX] (lane 1), BL40(iBL360) [ΔdamX ΔdedD(P_lac::gfp-dedD)] (lane 2), and BL40(iBL345) [ΔdamX ΔdedD] [P_lac::gfp-dedD^1–118] (lane 3) were obtained by growth as described for panel C [50 μM IPTG; BL38 and BL40(iBL360)] or J [250 μM IPTG; BL40(iBL345)] and used to prepare whole-cell extracts. For lanes 4 to 7, the BL40(iBL345) extract (lane 3) was diluted with that of BL38 (lane 1) to yield the fraction of the former indicated above each lane. Each lane contained 40 μg total protein. Fusion proteins were detected using anti-GFP (α-GFP) polyclonal antibodies. Bands corresponding to the fusions of interest are indicated by arrowheads. Migration of molecular mass standards (in kilodaltons) is indicated on the left. Division phenotypes (A to J) and relative band intensities (K) indicated that, relative to GFP-DedD, BL40 [ΔdamX ΔdedD] cells require a 2- to 4-fold higher level of SPOR-less GFP-DedD^1–118 to prevent cell chaining.