Function 
Peptidyl-prolyl cis-trans isomerase (PPIase) interconverts cis and trans isomers of proline.  PPIase functions as a protein folding chaperone.
-  PPIase Pin1 isomerizes phospho-serine/threonine proline motifs[1].  The deregulation of Pin1 may be involved in cancer and Alzheimer Disease.  Pin1 consists of 2 domains: the WW domain recognizes the pSer/pThr Pro motif and the PPIase domain contains the catalytic site.
 
-  PPIase PinA is an archaeal parvulin-like PPIase.
-  PPIase Mip (macrophage infectivity potentiator) is required for optimal infection of macrophages by some parasites[2].
 
-  PPIase SlyD acts as a chaperone and speeds up protein folding.
 
-  PPIase SlpA is a 2-domain protein containing an FK506-binding domain and a PPIase domain and a small insert-in-flap domain which acts as a chaperone[3].
 
For various types of PPIase see:
•	Cyclophilin
•	FK506 binding protein for SlyD
•      The Escherichia coli sensitive to lysis D (SlyD) protein
 
•      Multifaceted SlyD from Helicobacter pylori: implication in NiFe hydrogenase maturation 
  Disease 
Mutations in PPIase genes are associated with age-related diseases like cardiovascular diseases, atherosclerosis, diabetes type II, chronic kidney disease, neurodegredation, cancer and age-related macular degeneration[4].
  Structural highlights 
The phosphoserine containing peptide found in the heptad repeat of RNA polymerase II large subunit interacts with the WW domain of PPIase Pin1[5]. . Water molecules are shown as red spheres.
  3D Structures of peptidyl-prolyl cis-trans isomerase 
Peptidyl-prolyl cis-trans isomerase  3D structures