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 (By similarity). Widely expressed in aerial organs, at high levels in young rosette leaves and flowers, at low levels in older tissues. Mostly expressed in young tissues. Expressed in all parts of floral buds, but later confined to stigma and anthers. Belongs to the cyclophilin-type PPIase family.