title: The ATPases CopA and CopB both contribute to copper resistance of the thermoacidophilic archaeon Sulfolobus solfataricus.
abstract: Certain heavy metal ions such as copper and zinc serve as essential cofactors of many enzymes, but are toxic at high concentrations. Thus, intracellular levels have to be subtly balanced. P-type ATPases of the P(IB)-subclass play a major role in metal homeostasis. The thermoacidophile Sulfolobus solfataricus possesses two P(IB)-ATPases named CopA and CopB. Both enzymes are present in cells grown in copper-depleted medium and are accumulated upon an increase in the external copper concentration. We studied the physiological roles of both ATPases by disrupting genes copA and copB. Neither of them affected the sensitivity of S. solfataricus to reactive oxygen species, nor were they a strict prerequisite to the biosynthesis of the copper protein cytochrome oxidase. Deletion mutant analysis demonstrated that CopA is an effective copper pump at low and high copper concentrations. CopB appeared to be a low-affinity copper export ATPase, which was only relevant if the media copper concentration was exceedingly high. CopA and CopB thus act as resistance factors to copper ions at overlapping concentrations. Moreover, growth tests on solid media indicated that both ATPases are involved in resistance to silver.
authors.affiliation: Lehrstuhl für Biophysik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Völlmecke
authors.affiliation: Lehrstuhl für Biophysik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
authors.forename: Steffen L
authors.initials: SL
authors.lastname: Drees
authors.affiliation: Molecular Biology of Archaea, MPI für Terrestrische Mikrobiologie, Marburg, Karl-von-Frisch-Straße 10, D-35043 Marburg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Reimann
authors.affiliation: Molecular Biology of Archaea, MPI für Terrestrische Mikrobiologie, Marburg, Karl-von-Frisch-Straße 10, D-35043 Marburg, Germany.
authors.forename: Sonja-Verena
authors.initials: SV
authors.lastname: Albers
authors.affiliation: Lehrstuhl für Biophysik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Lübben
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017382:Reactive Oxygen Species / Q000378:metabolism; D048229:Sulfolobus solfataricus / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D027682:Cation Transport Proteins; D017382:Reactive Oxygen Species; D003300:Copper; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases