PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. [protein]-peptidylproline (omega=180) = [protein]-peptidylproline (omega=0) Interacts with RPD3. Present with 18600 molecules/cell in log phase SD medium. Belongs to the cyclophilin-type PPIase family. PPIase D subfamily.