Localization of the chaperone domain of FKBP52.
FKBP52, a multidomain peptidyl prolyl cis/trans-isomerase (PPIase), is found in complex with the chaperone Hsp90 and the co-chaperone p23. It displays both PPIase and chaperone activity in vitro. To localize these two activities to specific regions of the protein, we created and analyzed a set of fragments of FKBP52. The PPIase activity toward both peptides and proteins is confined entirely to domain 1 (amino acids 1-148). The chaperone activity, however, resides in the C-terminal part of FKBP52, mainly in the region between amino acids 264 and 400 (domain 3). Interestingly, this domain also contains the tetratricopeptide repeats, which are responsible for the binding to C-terminal amino acids of Hsp90. Competition assays with a C-terminal Hsp90 peptide suggest that the non-native protein and Hsp90 are bound by different regions within this domain.
Pirkl
F
F
Institut für Organische Chemie und Biochemie, Technische Universität München, 85747 Garching, Germany.
Fischer
E
E
Modrow
S
S
Buchner
J
J
D000818:Animals; D001667:Binding, Competitive; D002950:Citrate (si)-Synthase / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011817:Rabbits; D013379:Substrate Specificity; D022021:Tacrolimus Binding Proteins / Q000737:chemistry / Q000378:metabolism*
D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D010446:Peptide Fragments; D002950:Citrate (si)-Synthase; D022021:Tacrolimus Binding Proteins; C403485:tacrolimus binding protein 4; D019696:Peptidylprolyl Isomerase