Figure 4.

hPNPase effect on EcPNPase-dependent phenotypes. (A, B) Growth in minimal media of C-1a (pnp⁺), black symbols; C-5691 (Δpnp), empty symbols; C-6001 (PNPT1_Ec), grey symbols. (A) Cultures (N = 3) were grown at 37 °C with shaking in M9/supp measuring the optical density at intervals. The symbols indicated average with StD. After overnight incubation, cultures grown in M9 were discarded and the flasks stained with crystal violet to colour adherent cells (lower panel). Ec, C-1a (pnp⁺); Δ, C-5691 (Δpnp); Hs, C-6001 (PNPT1_Ec). (B) Cultures were grown at 37 °C with shaking in M9 (High Pi) or M9/2.5 (Low Pi) with 0.4% glucose measuring the optical density at intervals. The symbols indicated average with range (N = 2, High Pi) or with StD (N = 3, Low Pi). (C) Serial dilutions of overnight cultures were plated on LD-agar and incubated overnight at 37 °C in presence or absence of zeocin or H₂O₂. To test UV sensitivity, the plates were exposed to the indicated dose of UV rays (λ = 254 nm) in a Stratalinker 2400 (Stratagene) before incubation. Strains are indicated as in (A). (D) Serial dilutions of overnight cultures were plated on LD-agar and incubated overnight at 37 °C or 7 days at 15 °C. Strains are indicated as in A. (E) Streptomycin resistance mutation rate (µ) determined by fluctuation test on 12 independent cultures per strain.