May play a role in the transport of polypeptides both across the mitochondrial membranes and into the endoplasmic reticulum. A functional difference between SSA1 and SSA2 proteins is expected. SSA2 can participate in the ATP-dependent disassembly of clathrin-coated vesicles. Binds human HTN3/histatin-5, a peptide from saliva, and mediates its fungicidal activity. Interacts with NAP1. Present with 364000 molecules/cell in log phase SD medium. Belongs to the heat shock protein 70 family.