1MPQ

MALTOPORIN TREHALOSE COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.218 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Channel specificity: structural basis for sugar discrimination and differential flux rates in maltoporin.

Wang, Y.F.Dutzler, R.Rizkallah, P.J.Rosenbusch, J.P.Schirmer, T.

(1997) J Mol Biol 272: 56-63

  • DOI: 10.1006/jmbi.1997.1224
  • Primary Citation of Related Structures:  
    1AF6, 1MPQ

  • PubMed Abstract: 
  • Maltoporin (LamB) facilitates the diffusion of maltodextrins across the outer membrane of E. coli. The structural basis for the specificity of the channel is investigated by X-ray structure analysis of maltoporin in complex with the disaccharides sucrose, trehalose, and melibiose ...

    Maltoporin (LamB) facilitates the diffusion of maltodextrins across the outer membrane of E. coli. The structural basis for the specificity of the channel is investigated by X-ray structure analysis of maltoporin in complex with the disaccharides sucrose, trehalose, and melibiose. The sucrose complex, determined to 2.4 A resolution, shows that the glucosyl moiety is partly inserted into the channel constriction, while the bulky fructosyl residue appears to be hindered to enter the constriction, thus interfering with its further translocation. One of the glucosyl moieties of trehalose is found in a similar position as the glucosyl moiety of sucrose, whereas melibiose appears disordered when bound to maltoporin. A comparison with the previously reported maltoporin-maltose complex sheds light on the basis for sugar discrimination, and explains the different permeation rates observed for the saccharides.


    Related Citations: 
    • Crystal Structures of Various Maltooligosaccharides Bound to Maltoporin Reveal a Specific Sugar Translocation Pathway
      Dutzler, R., Wang, Y.F., Rizkallah, P., Rosenbusch, J.P., Schirmer, T.
      (1996) Structure 4: 127
    • Structural Basis for Sugar Translocation Through Maltoporin Channels at 3.1 A Resolution
      Schirmer, T., Keller, T.A., Wang, Y.F., Rosenbusch, J.P.
      (1995) Science 267: 512

    Organizational Affiliation

    Department of Microbiology, Biozentrum, University of Basel, Basel, CH-4056, Switzerland.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MALTOPORINA, B, C421Escherichia coliMutation(s): 0 
Gene Names: lamB
Membrane protein
Mpstruc
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Beta-Barrel Membrane Proteins: Porins and Relatives
Protein: 
LamB Maltoporin in complex with sucrose
Find proteins for P02943 (Escherichia coli (strain K12))
Explore P02943 
Go to UniProtKB:  P02943
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
alpha-D-glucopyranose-(1-1)-alpha-D-glucopyranoseD, E, F2 N/A Oligosaccharides Interaction
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900006
Query on PRD_900006
D, E, FtrehaloseOligosaccharide /  Nutrient

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.218 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 130α = 90
b = 212.2β = 90
c = 218.2γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
ROTAVATAdata reduction
X-PLORmodel building
X-PLORrefinement
CCP4data scaling
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-03-25
    Type: Initial release
  • Version 1.1: 2008-03-03
    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