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 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 2.1 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: https://doi.org/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. 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.


  • Organizational Affiliation

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


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
MALTOPORIN
A, B, C
421Escherichia coliMutation(s): 0 
Gene Names: LAMB
Membrane Entity: Yes 
UniProt
Find proteins for P02943 (Escherichia coli (strain K12))
Explore P02943 
Go to UniProtKB:  P02943
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02943
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-glucopyranose-(1-1)-alpha-D-glucopyranose
D, E, F
2N/A
Glycosylation Resources
GlyTouCan:  G92130SN
GlyCosmos:  G92130SN
Biologically Interesting Molecules (External Reference) 1 Unique
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

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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
  • Version 2.1: 2023-08-09
    Changes: Advisory, Database references, Refinement description, Structure summary