Crystal structure of a truncated form of FkpA from Escherichia coli

Experimental Data Snapshot

  • Resolution: 1.97 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 

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Structural and functional studies of FkpA from Escherichia coli, a cis/trans peptidyl-prolyl isomerase with chaperone activity.

Saul, F.A.Arie, J.P.Vulliez-le Normand, B.Kahn, R.Betton, J.M.Bentley, G.A.

(2004) J Mol Biol 335: 595-608

  • DOI: https://doi.org/10.1016/j.jmb.2003.10.056
  • Primary Citation of Related Structures:  
    1Q6H, 1Q6I, 1Q6U

  • PubMed Abstract: 

    The protein FkpA from the periplasm of Escherichia coli exhibits both cis/trans peptidyl-prolyl isomerase (PPIase) and chaperone activities. The crystal structure of the protein has been determined in three different forms: as the full-length native molecule, as a truncated form lacking the last 21 residues, and as the same truncated form in complex with the immunosuppressant ligand, FK506. FkpA is a dimeric molecule in which the 245-residue subunit is divided into two domains. The N-terminal domain includes three helices that are interlaced with those of the other subunit to provide all inter-subunit contacts maintaining the dimeric species. The C-terminal domain, which belongs to the FK506-binding protein (FKBP) family, binds the FK506 ligand. The overall form of the dimer is V-shaped, and the different crystal structures reveal a flexibility in the relative orientation of the two C-terminal domains located at the extremities of the V. The deletion mutant FkpNL, comprising the N-terminal domain only, exists in solution as a mixture of monomeric and dimeric species, and exhibits chaperone activity. By contrast, a deletion mutant comprising the C-terminal domain only is monomeric, and although it shows PPIase activity, it is devoid of chaperone function. These results suggest that the chaperone and catalytic activities reside in the N and C-terminal domains, respectively. Accordingly, the observed mobility of the C-terminal domains of the dimeric molecule could effectively adapt these two independent folding functions of FkpA to polypeptide substrates.

  • Organizational Affiliation

    Unité d'Immunologie Structurale (C.N.R.S. U.R.A. 2185), Institut Pasteur, 25 rue du Dr Roux, 75724 Paris cedex 15, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
FKBP-type peptidyl-prolyl cis-trans isomerase fkpA
A, B
224Escherichia coliMutation(s): 2 
Gene Names: FKPA OR B3347
Find proteins for P45523 (Escherichia coli (strain K12))
Explore P45523 
Go to UniProtKB:  P45523
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP45523
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B
Experimental Data & Validation

Experimental Data

  • Resolution: 1.97 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 37.03α = 90
b = 85.23β = 90
c = 160.74γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-01-13
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2024-04-03
    Changes: Data collection, Database references, Derived calculations, Refinement description