It is now apparent that the deletion of E303 in the DYT1 dystonia mutant TorsinA perturbs a critical helix at the cofactor interface (Demircioglu et al., 2016), providing an atomic-level rationale for the observation of reduced cross-linking of the conserved C-terminal TorsinA aromatic residues with the cofactor in the TorsinA disease variant (Brown et al., 2014), and the resulting failure to trigger ATP hydrolysis (Zhao et al., 2013) (for additional details on disease implications, see Rose et al., 2015; Cascalho et al., 2017). Here, TOR1A is linked to Dystonia.