title: Crystal structure of the long-chain fatty acid transporter FadL.
abstract: The mechanisms by which hydrophobic molecules, such as long-chain fatty acids, enter cells are poorly understood. In Gram-negative bacteria, the lipopolysaccharide layer in the outer membrane is an efficient barrier for fatty acids and aromatic hydrocarbons destined for biodegradation. We report crystal structures of the long-chain fatty acid transporter FadL from Escherichia coli at 2.6 and 2.8 angstrom resolution. FadL forms a 14-stranded beta barrel that is occluded by a central hatch domain. The structures suggest that hydrophobic compounds bind to multiple sites in FadL and use a transport mechanism that involves spontaneous conformational changes in the hatch.
authors.affiliation: Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA. lvandenberg@hms.harvard.edu
authors.forename: Bert
authors.initials: B
authors.lastname: van den Berg
authors.forename: Paul N
authors.initials: PN
authors.lastname: Black
authors.forename: William M
authors.initials: WM
authors.lastname: Clemons
authors.forename: Tom A
authors.initials: TA
authors.lastname: Rapoport
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D001692:Biological Transport; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D050612:Fatty Acid Transport Proteins; D005227:Fatty Acids / Q000378:metabolism*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D050612:Fatty Acid Transport Proteins; D005227:Fatty Acids; C065691:fadL protein, E coli