title: Structure of the ATPase subunit CysA of the putative sulfate ATP-binding cassette (ABC) transporter from Alicyclobacillus acidocaldarius.
abstract: CysA, the ATPase subunit of a putative sulfate ATP-binding cassette transport system of the gram-positive thermoacidophilic bacterium Alicyclobacillus acidocaldarius, was structurally characterized at a resolution of 2.0 Angstroms in the absence of nucleotides. In line with previous findings on ABC-ATPases the structures of the two monomers (called CysA-1 and CysA-2) in the asymmetric unit differ substantially in the arrangement of their individual (sub)domains. CysA-2 was found as a physiological dimer composed of two crystallographically related monomers that are arranged in an open state. Interestingly, while the regulatory domain of CysA-2 packs against its opposing domain that of CysA-1 undergoes a conformational change and, in the dimer, would interfere with the opposing monomer thereby preventing solute translocation. Whether this conformational state is used for regulatory purposes will be discussed.
authors.affiliation: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Scheffel
authors.forename: Ulrike
authors.initials: U
authors.lastname: Demmer
authors.forename: Eberhard
authors.initials: E
authors.lastname: Warkentin
authors.forename: Anja
authors.initials: A
authors.lastname: Hülsmann
authors.forename: Erwin
authors.initials: E
authors.lastname: Schneider
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ermler
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry*; D000251:Adenosine Triphosphatases / Q000737:chemistry*; D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D016937:Gram-Positive Endospore-Forming Rods / Q000201:enzymology / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
chemical_list: D018528:ATP-Binding Cassette Transporters; D000251:Adenosine Triphosphatases