Operational Principles for the Dynamics of the In Vitro ParA-ParB System
Fig 5
Dependence of bead speed on ϕ and ParA rebinding kinetics.
(A) Speed of bead versus time for undersaturating (ϕ < 1) and saturating (ϕ > 1) ParA concentrations. When the system is saturated, the bead attains a constant speed. In the undersaturated conditions, the bead shows a period of persistent acceleration. For both cases, non-cooperative rebinding of ParA was used with a rate of kr = 0.25 and c = 0.5. (B) The dependence of the final speed attained by the bead on the rate of rebinding, kr. When ϕ ⩾ 1 increasing kr reduces the final speed of the bead as there is increased ParA recovery in the wake region created by the bead. For ϕ ≲ 1, the final speed of the bead is greater than the case without any rebinding present (kr = 0) and reduces to a constant value as kr is increased (inset). (C) Dependence of the bead’s speed on the non-cooperative rebinding rate and ϕ. In the saturating regime (ϕ > 1) the bead can stall if the rebinding rate is sufficiently large (black curve with kr = 0.25) (D) Inclusion of cooperative rebinding (black curve with kc = 5.0) can stall the bead at lower values of ϕ compared to non-cooperative rebinding alone (red curve with kc = 0.0).