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Structure of the ATPase subunit CysA of the putative sulfate ATP‐binding cassette (ABC) transporter from Alicyclobacillus acidocaldarius
Author(s) -
Scheffel Frank,
Demmer Ulrike,
Warkentin Eberhard,
Hülsmann Anja,
Schneider Erwin,
Ermler Ulrich
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.04.017
Subject(s) - atp binding cassette transporter , protein subunit , pyrococcus horikoshii , dimer , nucleotide , chemistry , atpase , protein structure , biochemistry , crystallography , biophysics , biology , transporter , crystal structure , enzyme , gene , organic chemistry
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 Å 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.