Structure of the ATPase subunit CysA of the putative sulfate ATP-binding cassette (ABC) transporter from Alicyclobacillus acidocaldarius.
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.
Scheffel
Frank
F
Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, Institut für Biologie, Germany.
Demmer
Ulrike
U
Warkentin
Eberhard
E
Hülsmann
Anja
A
Schneider
Erwin
E
Ermler
Ulrich
U
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
D018528:ATP-Binding Cassette Transporters; D000251:Adenosine Triphosphatases