Prevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions (By similarity). Essential for proper development of trachea, spermatogonia and spermatocytes. First detectable expression is seen in the posterior part of the dorsal tracheal trunk at stage 14-15, which marks the beginning of terminal tracheation. In the larval gut, expression in proventriculus is stronger than in midgut and hindgut. Malpighian tubules shows low expression and late third instar larval imaginal disks and brain showed moderate expression. In larval ovary and testis, expression is strong in the posterior region. Expression first seen in late embryonic stages and continues in larval and adult stages. Flies are male and female sterile; reduction in numbers of primary and secondary spermatocytes. Belongs to the chaperonin (HSP60) family.