FIG 8.

Rod scaffold protein FlgJ remains stably associated with the basal body until it is dislodged by FlgH. Two 500-ml aliquots of TH20769 (flgJ8013::3×HA ΔflgH7662 ΔflgD6543 ΔaraBAD1001::flgH⁺ P_flhDC8089::tetR P_tetA) were grown to mid-log phase and induced to construct basal bodies by adding anhydrotetracycline (ATc). After 10 min, one culture received arabinose (Ara) to induce expression of the L-ring protein, FlgH. The other culture received saline. Following an additional 25 min of incubation, mRNA translation was blocked in both cultures by the addition of spectinomycin. Basal bodies from both cultures were purified and subjected to SDS-PAGE. Western blot analysis probing for FlgJ-HA revealed that without L-ring formation, FlgJ-HA remained associated with the basal body (lane 1). The culture, which was induced to express FlgH, had only a trace amount of FlgJ-HA associated with purified basal bodies (lane 2).