Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity. This cycle probably induces conformational changes in the client proteins, thereby causing their activation. Interacts dynamically with various co-chaperones that modulate its substrate recognition, ATPase cycle and chaperone function. Together with Hop and piwi, mediates canalization, also known as developmental robustness, likely via epigenetic silencing of existing genetic variants and suppression of transposon-induced new genetic variation. Required for piRNA biogenesis by facilitating loading of piRNAs into PIWI proteins. Homodimer (By similarity). Forms a complex with Hop and piwi; probably Hop mediates the interaction between piwi and Hsp83 (PubMed:21186352). Forms a complex including sicily, ND-42 and Hsp83; the complex is necessary to chaperone ND-42 in the cytoplasm before mitochondrial import; the interaction with sicily is direct and is dependent on its ATPase activity (PubMed:23509070). Interacts with shu (PubMed:22902557). Interacts with Nup358 (via TPR repeats); the interaction is required for the nuclear import of the sesquiterpenoid juvenile hormone receptor Met (PubMed:27979731). Forms a complex with Dpit47 and Hsp70aa (PubMed:11493638). Interacts with mora (PubMed:31907206). In contrast to other major heat shock proteins, this one is also expressed at normal growth temperatures. It is also developmentally expressed during oogenesis. The TPR repeat-binding motif mediates interaction with TPR repeat-containing proteins. RNAi-mediated knockdown is lethal at third instar larva stage and shows decreased levels of sicily, ND-42, and ND-30. Belongs to the heat shock protein 90 family.