1MAL

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.240 
  • R-Value Work: 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


  • 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-s ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MALTOPORIN
A, B, C
421Escherichia coli (strain K12)Gene Names: lamB (malB)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Beta-Barrel Membrane Proteins: Porins and Relatives
Protein: 
LamB Maltoporin
Find proteins for P02943 (Escherichia coli (strain K12))
Go to UniProtKB:  P02943
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.217 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 131.890α = 90.00
b = 214.790β = 90.00
c = 220.190γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
X-PLORphasing
X-PLORmodel building
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

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

Revision History 

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