Co-chaperone required during oogenesis to repress transposable elements and prevent their mobilization, which is essential for the germline integrity. Acts via the piRNA metabolic process, which mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and Piwi proteins and govern the methylation and subsequent repression of transposons. Acts as a co-chaperone via its interaction with Hsp83/HSP90 and is required for the biogenesis of all three piRNA major populations (By similarity). Interacts with Hsp83. Belongs to the FKBP6 family. Although it contains a PPIase FKBP-type domain, does not show peptidyl-prolyl cis-trans isomerase activity.