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- ******************************************************************
- * Cyclophilin-type peptidyl-prolyl cis-trans isomerase signature *
- ******************************************************************
-
- Cyclophilin [1] is the major high-affinity binding protein in vertebrates
- for the immunosuppressive drug cyclosporin A (CSA). It exhibits a peptidyl-
- prolyl cis-trans isomerase activity (EC 5.2.1.8) (PPIase or rotamase). PPIase
- is an enzyme that accelerates protein folding by catalyzing the cis-trans
- isomerization of proline imidic peptide bonds in oligopeptides [2]. It is
- probable that CSA mediates some of its effects via an inhibitory action on
- PPIase. Cyclophilin is a cytosolic protein which belongs to a family [3,4,5]
- that also includes the following isozymes:
-
- - Cyclophilin B (or S-cyclophilin), a PPIase which is retained in an
- endoplasmic reticulum compartment.
- - Cyclophilin C, a cytoplasmic PPiase.
- - Mitochondrial matrix cyclophilin (cyp3).
- - A PPIase which seems specific for the folding of rhodopsin and is an
- integral membrane protein anchored by a C-terminal transmembrane region.
- This protein was first characterized in Drosophila (gene ninaA).
- - A bacterial periplasmic PPiase (gene ppiA).
- - A bacterial cytosolic PPiase (gene ppiB).
- - Natural-killer cell cyclophilin-related protein. This large protein (about
- 160 Kd) is a component of a putative tumor-recognition complex involved in
- the function of NK cells. It contains a cyclophilin-type PPiase domain.
-
- The sequences of the different forms of cyclophilin-type PPIases are well
- conserved. As a signature pattern, we selected a conserved region in the
- central part of these enzymes.
-
- -Consensus pattern: [FY]-x(2)-[STLV]-x-F-H-[RH]-[LIVM](2)-x(2)-F-[LIVM]-x-Q-
- [AG]-G
- -Sequences known to belong to this class detected by the pattern: ALL, except
- for yeast CYP4.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: FKBP's, a family of proteins that bind the immunosuppressive drug
- FK506, are also PPIases, but their sequence is not at all related to that of
- cyclophilin (see the section on FKBP).
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Stamnes M.A., Rutherford S.L., Zuker C.S.
- Trends Cell Biol. 2:272-276(1992).
- [ 2] Fischer G., Schmid F.X.
- Biochemistry 29:2205-2212(1990).
- [ 3] Trandinh C.C., Pao G.M., Saier M.H. Jr.
- FASEB J. 6:3410-3420(1992).
- [ 4] Galat A.
- Eur. J. Biochem. 216:689-707(1993).
- [ 5] Hacker J., Fischer G.
- Mol. Microbiol. 10:445456(1993).
-