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 

wwPDB Validation 3D Report Full Report


This is version 1.2 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: 10.1110/ps.0235103

  • 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 inc ...

    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.


    Related Citations: 
    • Degradation versus aggregation of misfolded maltose-binding protein in the periplasm of Escherichia coli
      Betton, J.M.,Sassoon, N.,Hofnung, M.,Laurent, M.
      (1998) J.Biol.Chem. 273: 8897
    • Folding of a mutant maltose-binding protein of Escherichia coli which forms inclusion bodies
      Betton, J.M.,Hofnung, M.
      (1996) J.Biol.Chem. 271: 8046


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MALTOSE-BINDING PROTEIN MUTANT MALE31
A, C
370Escherichia coli (strain K12)Gene Names: malE
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AEX9
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GLC
Query on GLC

Download SDF File 
Download CCD File 
A, C
ALPHA-D-GLUCOSE
C6 H12 O6
WQZGKKKJIJFFOK-DVKNGEFBSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.157 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 42.043α = 90.00
b = 89.115β = 90.00
c = 95.975γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
SCALEPACKdata scaling
REFMACrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-03-04
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance