Fig. 4.

SANS measurements of TePSI in the presence of Cyt c_HH or Cyt c₆. A, SANS data of trimeric TePSI (black line) and of TePSI-Cyt c_HH complexes (red line) obtained at a contrast of 5% D₂O. B, Magnification of the SANS data shown in Panel A for the q-region, where a different signal is observed for trimeric TePSI (black line) and TePSI-Cyt c_HH complexes (red line), respectively. C, Pair distance distribution functions P(r) obtained from the SANS data of trimeric TePSI (black line) and of TePSI-Cyt c_HH complexes (red line), respectively. For comparison, we also present the P(r) function (green line) calculated from the crystal structure of TePSI (pdb code 1jb0; Jordan et al., 2001). D, SANS data of trimeric TePSI (black line) and of a mixture of TePSI-Cyt c₆ complexes (orange line) obtained at a contrast of 5% D₂O. E, Comparison of the structure of the TePSI-Cyt c_HH complex reconstructed from the SANS data using the ATSAS routine (light blue spheres) with a crystal structure of the PSI-cytochrome complex taken from (Kölsch et al., 2018).