The plates were inoculated with 10 μL of the cell suspension mentioned above and incubated in swimming plates for 24 h or in swarming plates for 72 h at 30 °C. Flagellar basal bodies were isolated as described previously for other microorganisms (Aizawa et al., 1985; Terashima et al., 2006), with minor modifications. An overnight culture (grown in TBSW) was inoculated at a 100-fold

dilution into the same growth medium (1 L) and subsequently cultured for 4 h at 30 °C (OD600 nm=0.6). Cells were harvested in a cold sucrose solution (0.5 M sucrose, 50 mM Tris-Cl, pH 8.0) and converted MK2206 into spheroplasts by the addition of lysozyme and EDTA at a final concentration of 0.1 mg mL−1 and 2 mM, respectively. Lysis of spheroplasts was achieved by adding Triton X-100 from a 20% stock solution to a final concentration of 1% (w/v) and the suspension was incubated for 40 min at 4 °C, after which MgSO4 and Dnase I were added to a final concentration of 5 mM GS-1101 concentration and 0.1 mg mL−1, respectively. After the viscosity decreased, EDTA (5 mM) was added. Whole cells and cell debris were removed by centrifugation at 17 000 g for 20 min at 4 °C. The supernatant was incubated with polyethylene glycol 6000 and NaCl at a final concentration of 2% and 100 mM, respectively, and incubated for

1 h at 4 °C. The suspension was centrifuged at 27 000 g for 30 min at 4 °C. The pellet was suspended in 6 mL of Tris-Cl 10 mM, pH 8.0, EDTA 5 mM, 1% Triton X-100 (w/v), 5% glycerol (TET buffer). Cell debris were removed by centrifugation at 1000 g for 15 min at 4 °C. The supernatant was centrifuged at 100 000 g for 30 min and the pellet was suspended in 300 μL of TET buffer. This isolated fraction was further purified by molecular sieve filtration in a Sepharose CL-4B column (100 mm × 10 mm) as described previously (West & Dreyfus, 1997). The column was equilibrated with TET buffer that was filtered previously through Amicon (0.22 nm) and 0.5-mL fractions were collected at 4 °C. The protein concentration was determined using the method described previously (Bradford, 1976) and samples were analyzed

in sodium dodecyl sulfate polyacrylamide Adenosine triphosphate gel electrophoresis (SDS-PAGE) gels (Laemmli, 1970). The bands obtained were further analyzed by MS. The protein bands were excised from the Coomassie-stained SDS-PAGE gels, destained, reduced, carbamidomethylated, washed, digested with modified porcine trypsin (Promega, Madison, WI) and extracted as described previously (Xolalpa et al., 2007). MS analysis of the tryptic peptides was carried out using a 3200 Q TRAP hybrid tandem mass spectrometer (Applied Biosystems/MDS Sciex, Concord, ON, Canada), equipped with a nanoelectrospray ion source (NanoSpray II) and a MicroIonSpray II head. The instrument was coupled on line to a nano-Acquity Ultra Performance LC system (Waters Corporations, Milford, MA).