Fig. 3

RhsPC is delivered by binding to PAAR2. a Auto-proteolysis is essential for RhsPC delivery. Mutations that compromised aspartic protease activity abolished RhsPC secretion. FLAG-tagged RhsP (RhsP-F) and individual mutants in RDD (R1092, D1105, and D1127) were expressed from pBAD24 in ΔrhsP and the secretion of RhsP and its derivatives were examined by Western blot analysis of the total (Cell) and secreted proteins (Sup). b Validation of interaction between PAAR2 and PID with Co-IP. Epitope-labeled RhsP-F (pBAD24-rhsP-F), PID-F (pBAD24-PID-F), or PAAR2-V (pBAD24-paar2-V) was expressed in E. coli DH5α. PAAR2 tagged with VSV-G (PAAR2-V) was immuno-precipitated by FLAG-tagged RhsP (RhsP-F) or FLAG-tagged PID (PID-F). c PID is essential for RhsPC secretion. Western blot analysis of cell lysate (Cell) and supernatant proteins (Sup) of FLAG-tagged RhsP (RhsP-F) and its truncated derivatives (RhsPC-F or WHH domain-F) expressed in ΔrhsP or ΔrhsPΔpaar2