3PF1: E. Coli Fadl Asp348ala Mutant

Ligand-gated channels, in which a substrate transport pathway is formed as a result of the binding of a small-molecule chemical messenger, constitute a diverse class of membrane proteins with important functions in prokaryotic and eukaryotic organisms. Despite their widespread nature, no ligand-gated channels have yet been found within the outer membrane (OM) of Gram-negative bacteria. Here we show, using in vivo transport assays, intrinsic tryptophan fluorescence and X-ray crystallography, that high-affinity (submicromolar) substrate binding to the OM long-chain fatty acid transporter FadL from Escherichia coli causes conformational changes in the N terminus that open up a channel for substrate diffusion. The OM long-chain fatty acid transporter FadL from E. coli is a unique paradigm for OM diffusion-driven transport, in which ligand gating within a beta-barrel membrane protein is a prerequisite for channel formation.
PDB ID: 3PF1Download
MMDB ID: 90810
PDB Deposition Date: 2010/10/27
Updated in MMDB: 2011/07
Experimental Method:
x-ray diffraction
Resolution: 2.7  Å
Source Organism:
Similar Structures:
Biological Unit for 3PF1: monomeric; determined by author and by software (PISA)
Molecular Components in 3PF1
Label Count Molecule
Protein (1 molecule)
Long-chain Fatty Acid Transport Protein(Gene symbol: fadL)
Molecule annotation
Chemicals (6 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB