Fig 4.
Role of Ykn proteins in protection against exogenous SdpC. HB6098 (Pspac-sdpABC) cells were grown in minimal medium in the presence or absence of IPTG. At OD600 ∼ 1.0 to 1.2, cells were removed by centrifugation and ultrafiltration and ice-cold TCA was added to supernatants for a final concentration of 10%. The TCA precipitates were solubilized and neutralized with 0.1 M NaOH and spotted onto an 0.7% LB agar plate containing 0.5% xylose and the indicated lawn strains. Inhibition zones were detected after 10 h of incubation at 37°C. In spot cultures, 1 mM IPTG was used for the induction of SdpC. Xylose at a final concentration of 0.5% was added to all lawn plates to induce expression of the ykn operon.