Co-chaperone that binds to the molecular chaperone Hsp70 (SSA1 and SSA2). Regulates Hsp70 ATPase activity (By similarity). Required for recovery from heat shock. Interacts with HSC82, HSP104, MDY2, SSA1 AND SSA2. Present with 9424 molecules/cell in log phase SD medium. Belongs to the SGT family.