title: The saci_2123 gene of the hyperthermoacidophile Sulfolobus acidocaldarius encodes an ATP-binding cassette multidrug transporter.
abstract: Multidrug resistance (MDR) transporters are capable of secreting structurally and functionally unrelated toxic compounds from the cell. Among this group are ATP-binding cassette (ABC) transporters. These membrane proteins are typically arranged as either hetero- or homo-dimers of ABC half-transporters with each subunit consisting of a membrane domain fused at the C-terminus to an ATP-binding domain, or as full transporters in which the two subunits are fused into a single polypeptide. The saci_2123 gene of the thermoacidophilic archaeon Sulfolobus acidocaldarius is the only gene in the genome that encodes an ATP-binding cassette half-transporter, while a homologous gene is present in the genomes of S. solfataricus, S. tokodaii and S islandicus. Saci_2123 shares homology with well-characterized bacterial and mammalian MDR transporters. The saci_2132 gene is up-regulated when cells are exposed to drugs. A deletion mutant of saci_2132 was found to be more vulnerable to a set of toxic compounds, including detergents, antibiotics and uncouplers as compared to the wild-type strain, while the drug resistance could be restored through the plasmid-based expression of saci_2132. These data demonstrate that Saci_2132 is an archaeal ABC-MDR transporter and therefore it was termed Smr1 (Sulfolobus multidrug resistance transporter 1).
authors.affiliation: Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, Netherlands, a.j.m.driessen@rug.nl.
authors.forename: Nuan
authors.initials: N
authors.lastname: Yang
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000737:chemistry; D001692:Biological Transport; D019295:Computational Biology; D003902:Detergents / Q000737:chemistry; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D017353:Gene Deletion; D020869:Gene Expression Profiling; D019766:Genes, Archaeal; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D019642:RNA, Archaeal / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D016945:Sulfolobus acidocaldarius / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D000255:Adenosine Triphosphate; D000890:Anti-Infective Agents; D003902:Detergents; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D019642:RNA, Archaeal