1FKJ

ATOMIC STRUCTURE OF FKBP12-FK506, AN IMMUNOPHILIN IMMUNOSUPPRESSANT COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Work: 0.162 
  • R-Value Observed: 0.162 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Comparative X-ray structures of the major binding protein for the immunosuppressant FK506 (tacrolimus) in unliganded form and in complex with FK506 and rapamycin.

Wilson, K.P.Yamashita, M.M.Sintchak, M.D.Rotstein, S.H.Murcko, M.A.Boger, J.Thomson, J.A.Fitzgibbon, M.J.Black, J.R.Navia, M.A.

(1995) Acta Crystallogr D Biol Crystallogr 51: 511-521

  • DOI: https://doi.org/10.1107/S0907444994014514
  • Primary Citation of Related Structures:  
    1FKJ, 1FKK, 1FKL

  • PubMed Abstract: 

    FK506 (tacrolimus) is a natural product now approved in the US and Japan for organ transplantation. FK506, in complex with its 12 kDa cytosolic receptor (FKBP12), is a potent agonist of immunosuppression through the inhibition of the phosphatase activity of calcineurin. Rapamycin (sirolimus), which is itself an immunosuppressant by a different mechanism, completes with FK506 for binding to FKBP12 and thereby acts as an antagonist of calcineurin inhibition. We have solved the X-ray structure of unliganded FKBP12 and of FKBP12 in complex with FK506 and with rapamycin; these structures show localized differences in conformation and mobility in those regions of the protein that are known, by site-directed mutagenesis, to be involved in calcineurin inhibition. A comparison of 16 additional X-ray structures of FKBP12 in complex with FKBP12-binding ligands, where those structures were determined from different crystal forms with distinct packing arrangements, lends significance to the observed structural variability and suggests that it represents an intrinsic functional characteristic of the protein. Similar differences have been observed for FKBP12 before, but were considered artifacts of crystal-packing interactions. We suggest that immunosuppressive ligands express their differential effects in part by modulating the conformation of FKBP12, in agreement with mutagenesis experiments on the protein, and not simply through differences in the ligand structures themselves.


  • Organizational Affiliation

    Vertex Pharmaceuticals Incorporated, Cambridge, MA 02139-4211, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
FK506 BINDING PROTEIN107Homo sapiensMutation(s): 0 
EC: 5.2.1.8
UniProt & NIH Common Fund Data Resources
Find proteins for P62942 (Homo sapiens)
Explore P62942 
Go to UniProtKB:  P62942
PHAROS:  P62942
GTEx:  ENSG00000088832 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP62942
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
FK5
Query on FK5

Download Ideal Coordinates CCD File 
B [auth A]8-DEETHYL-8-[BUT-3-ENYL]-ASCOMYCIN
C44 H69 N O12
QJJXYPPXXYFBGM-LFZNUXCKSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
FK5 BindingDB:  1FKJ Ki: 0.4 (nM) from 1 assay(s)
Kd: min: 0.2, max: 0.4 (nM) from 2 assay(s)
IC50: min: 2.3, max: 1000 (nM) from 3 assay(s)
EC50: 0.9 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Work: 0.162 
  • R-Value Observed: 0.162 
  • Space Group: P 42 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.1α = 90
b = 58.1β = 90
c = 55.7γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
MANUFACTURERdata reduction
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1995-12-07
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references, Derived calculations, Other