TOR1A is a member of the AAA family of adenosine triphosphatases (ATPases), is related to the Clp protease/heat shock family and is expressed prominently in the substantia nigra pars compacta. Mutations in this gene result in the autosomal dominant disorder, torsion dystonia 1. Recombinant human TOR1A protein, His-tag at N-terminus, was expressed in E.coli.