ARF1 and infection: In addition, recombinant full-length LpRalFY326D was unable to activate Arf1 in the presence of liposomes (kobs = 9±1.2 10−5 s−1 at 0.4 μM myrArf1 and 0.2 μM LpRalFY326D, to be compared to 4.7±1.0 10−2 s−1 for LpRalF under the same conditions) and Legionella ΔralF expressing full-length M45-tagged LpRalFY326D failed to recruit Arf1 at the LCV during infection (Figure 5F).