This gene represents the human homolog of the bacterial arsA gene, encoding the arsenite-stimulated ATPase component of the arsenite transporter responsible for resistance to arsenicals. This protein is also a central component of a transmembrane domain (TMD) recognition complex (TRC) that is involved in the post-translational delivery of tail-anchored (TA) proteins from the cytosol to the endoplasmic reticulum (ER). It recognizes and selectively binds the TMD of TA proteins in the cytosol, and delivers them to the ER for insertion.