function:Binds specifically to cytosolic chaperonin (c-CPN) and transfers target proteins to it. Binds to nascent polypeptide chain and promotes folding in an environment in which there are many competing pathways for nonnative proteins.,similarity:Belongs to the prefoldin subunit beta family.,subunit:Heterohexamer of two PFD-alpha type and four PFD-beta type subunits.,