1LAX

CRYSTAL STRUCTURE OF MALE31, A DEFECTIVE FOLDING MUTANT OF MALTOSE-BINDING PROTEIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.159 

wwPDB Validation   3D Report Full Report


This is version 2.2 of the entry. See complete history


Literature

Crystal structure of a defective folding protein

Saul, F.A.Mourez, M.Vulliez-le Normand, B.Sassoon, N.Bentley, G.A.Betton, J.M.

(2003) Protein Sci 12: 577-585

  • DOI: https://doi.org/10.1110/ps.0235103
  • Primary Citation of Related Structures:  
    1LAX

  • PubMed Abstract: 

    Maltose-binding protein (MBP or MalE) of Escherichia coli is the periplasmic receptor of the maltose transport system. MalE31, a defective folding mutant of MalE carrying sequence changes Gly 32-->Asp and Ile 33-->Pro, is either degraded or forms inclusion bodies following its export to the periplasmic compartment. We have shown previously that overexpression of FkpA, a heat-shock periplasmic peptidyl-prolyl isomerase with chaperone activity, suppresses MalE31 misfolding. Here, we have exploited this property to characterize the maltose transport activity of MalE31 in whole cells. MalE31 displays defective transport behavior, even though it retains maltose-binding activity comparable with that of the wild-type protein. Because the mutated residues are in a region on the surface of MalE not identified previously as important for maltose transport, we have solved the crystal structure of MalE31 in the maltose-bound state in order to characterize the effects of these changes. The structure was determined by molecular replacement methods and refined to 1.85 A resolution. The conformation of MalE31 closely resembles that of wild-type MalE, with very small displacements of the mutated residues located in the loop connecting the first alpha-helix to the first beta-strand. The structural and functional characterization provides experimental evidence that MalE31 can attain a wild-type folded conformation, and suggest that the mutated sites are probably involved in the interactions with the membrane components of the maltose transport system.


  • Organizational Affiliation

    Unité d'Immunologie Structurale, Unité de Repliement et Modélisation des Protéines, Institut Pasteur, CNRS URA 2185, 75724 Paris Cedex 15, France.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
MALTOSE-BINDING PROTEIN MUTANT MALE31A,
B [auth C]
370Escherichia coliMutation(s): 2 
Gene Names: MALE
UniProt
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Explore P0AEX9 
Go to UniProtKB:  P0AEX9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0AEX9
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranoseC [auth B],
D
2N/A
Glycosylation Resources
GlyTouCan:  G07411ON
GlyCosmos:  G07411ON
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.159 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.043α = 90
b = 89.115β = 90
c = 95.975γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
REFMACrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-03-04
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2021-10-27
    Changes: Database references, Structure summary
  • Version 2.2: 2023-08-16
    Changes: Data collection, Refinement description