Catalyzes the cis-trans isomerization of peptidyl prolyl bonds and accelerates protein folding (PubMed:9440528, PubMed:10631007). Also exhibits chaperone-like activity (PubMed:10631007). In vitro, can use oligopeptides such as N-succinyl-Ala-Leu-Pro-Phe-p-nitroanilide and N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide as substrates (PubMed:9440528, PubMed:10631007). [protein]-peptidylproline (omega=180) = [protein]-peptidylproline (omega=0) Inhibited by FK506 but not by cyclosporine. Thermostable. Contains an N-terminal PPIase domain and an IF (Insert in the Flap) domain. The IF domain, formed by an insert in the flap loop, is required for the chaperone-like activity but not for the PPIase activity. Belongs to the FKBP-type PPIase family. Extended N-terminus.