3D model modeling for PS1 G209A. Differences of normal and mutant PSEN1 have been highlighted in the black circle, and glycine was labeled with yellow, while alanine was labeled with yellow. The C-terminal pert of normal and abnormal proteins were overlapped, while significant differences could be seen in the N-terminal part, suggesting that the mutation could result significant conformational changes in the TM structure of PSEN1. a Differences between normal PSEN1 and PSEN1 G209A, focused on all over the protein. b Differences between normal and mutant PSEN1, focused on the TM-IV region.