title: Crystal structure of the Alcanivorax borkumensis YdaH transporter reveals an unusual topology.
abstract: The potential of the folic acid biosynthesis pathway as a target for the development of antibiotics has been clinically validated. However, many pathogens have developed resistance to these antibiotics, prompting a re-evaluation of potential drug targets within the pathway. The ydaH gene of Alcanivorax borkumensis encodes an integral membrane protein of the AbgT family of transporters for which no structural information was available. Here we report the crystal structure of A. borkumensis YdaH, revealing a dimeric molecule with an architecture distinct from other families of transporters. YdaH is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm to halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins that suggest a plausible pathway for substrate transport. Further analyses also suggest that YdaH could act as an antibiotic efflux pump and mediate bacterial resistance to sulfonamide antimetabolite drugs.
authors.affiliation: Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Jani Reddy
authors.initials: JR
authors.lastname: Bolla
authors.affiliation: Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Chih-Chia
authors.initials: CC
authors.lastname: Su
authors.affiliation: Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Jared A
authors.initials: JA
authors.lastname: Delmar
authors.affiliation: Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Abhijith
authors.initials: A
authors.lastname: Radhakrishnan
authors.affiliation: Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Nitin
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Tsung-Han
authors.initials: TH
authors.lastname: Chou
authors.affiliation: Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Long
authors.affiliation: NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Building 436E, Argonne National Laboratory, 9700S. Cass Avenue, Argonne. Illinois 60439, USA.
authors.forename: Kanagalaghatta R
authors.initials: KR
authors.lastname: Rajashankar
authors.affiliation: 1] Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA [2] Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Yu
mesh_terms: D053521:Alcanivoraceae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000890:Anti-Infective Agents / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005492:Folic Acid / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D013418:Sulfamethazine / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D013418:Sulfamethazine; D005492:Folic Acid