Endoplasmic reticulum translocase required to remove mitochondrial transmembrane proteins mistargeted to the endoplasmic reticulum. Acts as a dislocase that mediates the ATP-dependent extraction of mislocalized mitochondrial transmembrane proteins from the endoplasmic reticulum membrane. Specifically binds mitochondrial tail-anchored transmembrane proteins: has an atypically large substrate-binding pocket that recognizes and binds moderately hydrophobic transmembranes with short hydrophilic lumenal domains (By similarity). Involved in controlling nuclear calcium ion levels. Required for cytokinesis and stabilizing microtubules (PubMed:12058018). Required for assembly of the forespore membrane (PubMed:16394583). Involved in calcium transport to the endoplasmic reticulum (PubMed:22132152). [protein]-with a C-terminal TM segment(out) + ATP + H2O = [protein]-with a C-terminal TM segment(in) + ADP + H(+) + phosphate Contains a large substrate-binding pocket that recognizes alpha-helical transmembranes, which alternately faces the endoplasmic reticulum lumen and cytosol, while remaining accessible to the lipid bilayer through a lateral opening. The translocase alternates between two conformations: inward-open (E1) and outward-open (E2) states. Undergoes a series of conformational changes with ATP-binding, phosphorylation of the Asp active site and subsequent dephosphorylation in a Post-Albers cycle (i.e., E1 -> E1-ATP -> E1P-ADP -> E1P -> E2P -> E2-Pi -> E1). A substrate transmembrane helix with a short, preferentially positively charged lumenal segment binds to the outward-open pocket and the E2P-to-E1 transition flips the transmembrane by a switch from the outward-open to inward-open conformation. Increased levels of intracellular calcium. Impaired ATP-dependent calcium transport in endoplasmic reticulum (ER) membranes, but up-regulated vacuolar calcium transport. Sensitive to ER stress inducers DTT and tunicamycin, which inhibit the protein disulfide bond formation and N-glycosylation, respectively, and is thus sensitive to accumulation of misfolded proteins in the ER. Stimulated calcineurin phosphatase activity (PubMed:22132152). Cells conjugate to form zygotes at a lower efficiency than wild-type and they do not sporulate (PubMed:16394583). Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type V subfamily.