Figure 4. Grafting stable native contacts between PpiB and PpiA interconverted folding behaviours.

• A
  Pipeline for selecting residues that affect folding behaviour using the Frustratometer and 3D structures of PpiB (PDB 2NUL; 1LOP) and PpiA (PDB 1V9T; 1VAI; 1J2A) to test with grafting (details in Dataset EV7).
• B
  Highly stabilized, dissimilar native contacts indicated on a linear map with the secondary structural elements on top.
• C
  The side chains of native contact residues (green: PpiB; orange: PpiA) indicated on their 3D structure.
• D
  The native contact grafting scheme between PpiB and PpiA to test their role on folding behaviour.
• E
  Folding kinetics of PpiB and PpiA grafted mutants, at 4°C, as in Fig 2 (see also Dataset EV3). n = 2–4, biological repeats.
• F
  In vivo secretion of the indicated PpiX‐PhoA fusion proteins in MC4100 cells carrying SecY_prlA4EG. Secretion is expressed as pmol fusion protein secreted from PhoA activity calculations after removing background (uninduced cells) per pmol protein expressed from western blot analysis in 10⁸ cells (Fig EV4E, Dataset EV9). n = 6 (biological triplicates with 3 technical replicates each, s.d.).

Source data are available online for this figure.