1MAL

STRUCTURAL BASIS FOR SUGAR TRANSLOCATION THROUGH MALTOPORIN CHANNELS AT 3.1 ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.217 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

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: 512-514

  • DOI: 10.1126/science.7824948
  • Primary Citation of Related Structures:  
    1MAL

  • PubMed Abstract: 
  • Trimeric maltoporin (LamB protein) facilitates the diffusion of maltodextrins across the outer membrane of Gram-negative bacteria. The crystal structure of maltoporin from Escherichia coli, determined to a resolution of 3.1 angstroms, reveals an 18-stranded, antiparallel beta-barrel that forms the framework of the channel ...

    Trimeric maltoporin (LamB protein) facilitates the diffusion of maltodextrins across the outer membrane of Gram-negative bacteria. The crystal structure of maltoporin from Escherichia coli, determined to a resolution of 3.1 angstroms, reveals an 18-stranded, antiparallel beta-barrel that forms the framework of the channel. Three inwardly folded loops contribute to a constriction about halfway through the channel. Six contingent aromatic residues line the channel and form a path from the vestibule to the periplasmic outlet. Soaking of a crystal with maltotriose revealed binding of the sugar to this hydrophobic track across the constriction, which suggests that maltose and linear oligosaccharides may be translocated across the membrane by guided diffusion along this path.


    Related Citations: 
    • Crystallization and Preliminary X-Ray Characterization of Maltoporin from E.Coli
      Stauffer, K.A., Page, M.P.G., Hardmeyer, A., Keller, T.A., Pauptit, R.A.
      (1990) J Mol Biol 211: 297

    Organizational Affiliation

    Department of Structural Biology, University of Basel, Switzerland.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MALTOPORINA, B, C421Escherichia coliMutation(s): 0 
Find proteins for P02943 (Escherichia coli (strain K12))
Explore P02943 
Go to UniProtKB:  P02943
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.217 
  • R-Value Observed: 0.217 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 131.89α = 90
b = 214.79β = 90
c = 220.19γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 1994-11-24 
  • Released Date: 1995-12-31 
  • Deposition Author(s): Schirmer, T.

Revision History  (Full details and data files)

  • Version 1.0: 1995-12-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance