This domain is found at the C-terminal end of Torsin-1A from humans (TOR1A), an AAA+ ATPase that resides in the endoplasmic reticulum and the contiguous perinuclear space primarily in nerve cells. TOR1A needs the AAA+-like proteins Lamina-associated protein 1 (LAP1) or Luminal domain like LAP1 (LULL1) to catalyze ATP hydrolysis. A single amino acid deletion in the domain represented in this entry is known to be at the root of primary dystonia, probably by weakening these interactions. This small domain forms a three-helix bundle [1].

1: Structures of TorsinA and its disease-mutant complexed with an activator reveal the molecular basis for primary dystonia. Demircioglu FE, Sosa BA, Ingram J, Ploegh HL, Schwartz TU; Elife. 2016; [Epub ahead of print] PMID:27490483