This family comprises of several prefoldin subunits. The biogenesis of the cytoskeletal proteins actin and tubulin involves interaction of nascent chains of each of the two proteins with the oligomeric protein prefoldin (PFD) and their subsequent transfer to the cytosolic chaperonin CCT (chaperonin containing TCP-1). Electron microscopy shows that eukaryotic PFD, which has a similar structure to its archaeal counterpart, interacts with unfolded actin along the tips of its projecting arms. In its PFD-bound state, actin seems to acquire a conformation similar to that adopted when it is bound to CCT [1].

1: Structure of eukaryotic prefoldin and of its complexes with unfolded actin and the cytosolic chaperonin CCT. Martin-Benito J, Boskovic J, Gomez-Puertas P, Carrascosa JL, Simons CT, Lewis SA, Bartolini F, Cowan NJ, Valpuesta JM; EMBO J 2002;21:6377-6386. PMID:12456645