Fig. 5: N-terminal α-helix conformational changes in CDTa and Ia.

a Secondary structures of the CDTa crystal structure in the apo state (PDB ID: 2WN6) and the CDTa cryo-EM structure in the CDTb-pore complex (PDB ID: 7VNJ). b Secondary structures of the Ia crystal structure in the apo state (PDB ID: 1GIQ) and the Ia cryo-EM structure in the complex with Ib-pore (PDB ID: 6KLO). In both (a), (b), the dotted line indicates residues whose structures were not built. The thick line indicates residues without secondary structure. Residues of the α-helix unfolded in the complex are shown in blue. c Three-dimensional structures of the apo state (gold) and CDTb-bound CDTa (red). d Three-dimensional structures of the apo state (gold) and Ib-bound Ia (red).