Endoplasmic reticulum co-chaperone required for the of virulence factors such as PG1, the major endopolygalacturonase produced during the infection of tomato plants. The TPR repeats mediate interaction with unfolded polypeptides and the J-domain is essential to stimulate the ATPase activity of the chaperone and to increase its substrate affinity during the folding cycle. Shows increased sensitivity to the N-glycosylation inhibitor tunicamycin and leads to a significant attenuation of the virulence on tomato plants (PubMed:26487566). Accumulates significantly less fungal biomass in infected plants and leads to significant decrease in secretion of PG1, the major endopolygalacturonase produced during the infection of tomato plants (PubMed:26487566).