Acts as a chaperone. In vitro binds to human CD209 (DC-SIGN) and may help mediate adherence to host cells (PubMed:21203928). Able to bind to host (human) CD209 in vitro (PubMed:21203928). Also present in extracytoplasmic vesicles (PubMed:21364279). Although thought of as a cytoplasmic chaperone this protein is routinely found extracellularly in the absence of cell lysis (PubMed:21364279) (By similarity). By stress conditions e.g. heat shock. Belongs to the heat shock protein 70 family.