Figure 5. The X-ray structure of M4N.
(a) The three chains A, B and C in the asymmetric unit are colored green, blue and yellow, respectively. Chains A and B form a dimer. (b) Superposition of the three chains. Only Cα traces are shown for clarity. (c) Superposition of M4N (chain A, green) and the designed consensus TPR CTPR3 (PDB: 1na0, chain A, gray).
Figure 5—figure supplement 1. The interaction of M4N molecules in the crystal.
(a) Five adjacent ASUs are depicted. Chain A (green) and B (blue) form a dimer, while chain C (yellow) packs its C-terminus to the N-termini of chains A and B. (b) Top view. (c) An additional ASU (top-left) is shown to demonstrate the packing of N-termini of chains C.
Figure 5—figure supplement 2. Urea denaturation of designed TPR repeats.
Urea-induced equilibrium unfolding at 23°C was monitored by circular dichroism at 222 nm. Data were converted to the fraction of unfolded protein fU and fitted to a two-state model. The protein concentration was 15 µM. See Supplement file 1F for obtained parameters.
Figure 5—figure supplement 3. Mass spectrometry (MS) analysis of M4N.
The M4N fragment with a mass of 12733.533 Da in MS is underlined and highlighted in blue (theoretical mass 12733.77 Da). The C-terminus of M4N as observed in the crystal structure is marked by a red arrow.