PPIases are ubiquitous in living organisms. While 3 families of PPIases, cyclophilin (CyP), FK506 binding protein (FKBP) and parvulin (Pvn), have been studied in detail in Eukarya and Bacteria (eubacteria), little is known about archaeal PPIases. Among 2 cyclophilins found in Archaea, only Halobacterium cyclophilin (HcCyP19) has been characterized. It is a cyclosporin A (CsA) sensitive CyP with a MW of 19.4kDa. The PPIase activity and CsA sensitivity of this CyP is higher at higher salt… CONTINUE READING