Exemplary force–extension
traces from steered molecular dynamics simulations. Plots represent
the three types of rupture events observed in CttA-XDoc:CohE and ScaB-XDoc:CohE
simulations. (A) For CttA-XDoc:CohE, one-step rupture events were
observed in 57 out of 75 replicas. (B) For ScaB-XDoc:CohE, one step
rupture events were observed in 34 out of 75 replica simulations.
In the one-step event, all three domains (Coh, Doc, Xmod) remained
intact following rupture. (C) For CttA-XDoc:CohE, a destabilization
of Doc during breakage was observed in 16 out of 75 replicas. (D)
For ScaB-XDoc:CohE, Doc destabilization occurred in 39 out of 75 replicas.
Doc partial unfolding led to multipeak force vs extension traces that
were highly variable in replica simulations. (E) For CttA-XDoc:CohE,
Xmod unfoding was observed in 2 out of 75 replicas. (F) For ScaB-XDoc:CohE,
Xmod unfolding was also observed in 2 out of 75 replicas. Xmod unfolding
led to multipeak traces that were variable in each trajectory. The
first and largest peak in these cases corresponded to the loss of
contact between Xmod and Doc insert regions.