1PV6

Crystal structure of lactose permease


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.50 Å
  • R-Value Free: 0.337 
  • R-Value Work: 0.294 
  • R-Value Observed: 0.294 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure and mechanism of the lactose permease of Escherichia coli

Abramson, J.Smirnova, I.Kasho, V.Verner, G.Kaback, H.R.Iwata, S.

(2003) Science 301: 610-615

  • DOI: 10.1126/science.1088196
  • Primary Citation of Related Structures:  
    1PV6, 1PV7

  • PubMed Abstract: 
  • Membrane transport proteins that transduce free energy stored in electrochemical ion gradients into a concentration gradient are a major class of membrane proteins. We report the crystal structure at 3.5 angstroms of the Escherichia coli lactose permease, an intensively studied member of the major facilitator superfamily of transporters ...

    Membrane transport proteins that transduce free energy stored in electrochemical ion gradients into a concentration gradient are a major class of membrane proteins. We report the crystal structure at 3.5 angstroms of the Escherichia coli lactose permease, an intensively studied member of the major facilitator superfamily of transporters. The molecule is composed of N- and C-terminal domains, each with six transmembrane helices, symmetrically positioned within the permease. A large internal hydrophilic cavity open to the cytoplasmic side represents the inward-facing conformation of the transporter. The structure with a bound lactose homolog, beta-D-galactopyranosyl-1-thio-beta-D-galactopyranoside, reveals the sugar-binding site in the cavity, and residues that play major roles in substrate recognition and proton translocation are identified. We propose a possible mechanism for lactose/proton symport (co-transport) consistent with both the structure and a large body of experimental data.


    Organizational Affiliation

    Department of Biological Sciences, Imperial College London, London SW7 2AZ, UK.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Lactose permeaseA, B417Escherichia coliMutation(s): 1 
Membrane Entity: Yes 
UniProt
Find proteins for P02920 (Escherichia coli (strain K12))
Explore P02920 
Go to UniProtKB:  P02920
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.50 Å
  • R-Value Free: 0.337 
  • R-Value Work: 0.294 
  • R-Value Observed: 0.294 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 101.351α = 90
b = 125.845β = 90
c = 188.118γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
CNSrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-08-12
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance