Membrane binding of IcmQ.
A. IcmQ binds efficiently to floated vesicles (left), while IcmQ-tr does not bind to membranes and is present in the pellet (right) in this qualitative assay.
B. IcmQ-tr (grey line) does not release calcein from vesicles, while IcmQ (blue line) is able to release trapped dye molecules as monitored by increased fluorescence.
C. IcmQ binding to vesicles is greatly diminished when membranes do not contain an acidic phospholipid.
D. Higher salt diminishes IcmQ binding to vesicles made with an acidic phospholipid (DMPG).
E. Molecular dynamics simulations show that Rm-IcmQ may bind to the membrane surface using electrostatic interactions.
See also Figures S6, S7 and S8.