Fig. 6: AlphaFold3 prediction of the Tad motor subcomplex.
From: Conformational changes in the motor ATPase CpaF facilitate a rotary mechanism of Tad pilus assembly
A Composite model of the Tad motor subcomplex in which AlphaFold predicted CpaF and PilA were replaced and manually docked with the cryo-EM expanded structure of CpaF and the PilA filament (PDB: 8U1K), respectively. B AlphaFold3 predicted Tad ATPase-platform interface depicting secondary structural elements α5 (N189-V200), loop 8 (S201-P212), and the extended pore loop (T325-T337) in CpaF that engage the T2SSF domains of CpaG and CpaH. C Height differences in the extended pore loops within the asymmetric unit of each structure. Each chain is labelled from a to c. The height between the extended pore loop of chain a and c is indicated for each structure. D Expanded and compact CpaF structures and the AlphaFold predicted platform complex colored by Coulombic potential, contoured from +10 (blue) to −10 (red) kT/e. E Simplified view of the composite model in which the AlphaFold predicted heterotrimer CpaG-CpaH forms a central shaft to accommodate three PilA subunits from the PilA filament structure. Each CpaGH heterodimer is separated by a ~ 22 Å gap that is mediated by the N-terminal helix of CpaH to facilitate PilA entry into or exit from the shaft within the inner membrane. C C-terminal end, N N-terminal end.
