Peptidyl-prolyl cis-trans isomerase D (PPID)

PPIase that catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and might thus assist protein folding (PubMed:11350175, PubMed:20676357). Proposed to function as a co-chaperone in HSP90 complexes such as in unligated steroid receptors heterocomplexes.

Different co- chaperones seem to compete for association with HSP90 thus establishing distinct HSP90-co-chaperone-receptor complexes with the capability to exert tissue-specific receptor action control. May have a preference for nitric oxide complexes and isn't found in glucocorticoid receptor complexes.