Potential non-catalytic subunit for a heteromeric phospholipid translocase (PLT) CRF1-DNF3, implicated in the translocation of phospholipids from the outer to the inner leaflet of membrane bilayers. Shares an essential function for cell growth with PLTs CDC50-DRS2 and LEM3-DNF1/2. May be involved in transport from early endosomes to the trans-Golgi network (TGN). Interacts with DNF3; interaction is required for proper expression and endoplasmic reticulum (ER) export of either partner. Present with 4510 molecules/cell in log phase SD medium. Belongs to the CDC50/LEM3 family.