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) Binds cyclosporin A (CsA). CsA mediates some of its effects via an inhibitory action on PPIase. Belongs to the cyclophilin-type PPIase family. Was originally (PubMed:1623198) reported to be isolated from an A.thaliana cDNA library. PubMed:9426607 authors have assigned that the sequence has been amplified from an other contaminating organism.