Molecular chaperone capable of stabilizing a range of proteins. Seems to fulfill an ATP-independent, HSP70-like function in archaeal de novo protein folding (By similarity). Heterohexamer of two alpha and four beta subunits. Belongs to the prefoldin subunit alpha family. Was originally thought to originate from S.solfataricus strain P1, but the culture was contaminated with S.acidocaldarius.