Fig. 6: Electrostatic reorganization from CIII2CIV2 to CIII2CIV1 supercomplex upon QCR6 deletion.
The electrostatic potential map of CIII2CIV2 and CIII2CIV1 complex in the WT and ∆QCR6 supercomplex, where electrostatic surfaces at a potential of 0.5kBT per charge and a potential of −0.5kBT per charge are given in blue and red, respectively. Starting from the wild type CIII2CIV2 (A), the hypothetical impact of structural changes from CIII2CIV2 → CIII2CIV1 on the electrostatic properties is examined stepwise (B) by first removing a single copy of CIV (C) then deleting QCR6 (D), followed by adjustment on the remaining CIV’s position based on the cryo-EM information in Supplementary Fig. 26. Visual inspection of the four iso-surfaces show negligible differences in the vicinity of CIII and CIV. The cumulative density function (CDF) for negative electrostatic potential values, denoted as felec, was determined (see Methods: Analyzes details). CDFs for structures in panels (B), (C), and (E) are denoted as felecB, felecC, and felecE, respectively. The pairwise difference between these distributions, presented in (F), show that deletion of QCR6 expectedly reduces the strength of the electronegativity as from (B) to (C). The reorganization of the CIII2CIV structure (E) makes the assembly more electronegative than the CIV-deleted CIII2CIV2 structure in (C). Source data are provided as a Source Data file.
