PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Combines RNA-binding and PPIase activities. [protein]-peptidylproline (omega=180) = [protein]-peptidylproline (omega=0) Inhibited by cyclosporin A. The N-terminal RRM domain binds to nucleic acids including single-stranded DNA and RNA homopolymers poly(A), poly(G) and poly(U), but not to poly(C) nor double-stranded DNA. Binds most strongly to G-rich RNA species. Belongs to the cyclophilin-type PPIase family. PPIase E subfamily.