The ATPases CopA and CopB both contribute to copper resistance of the thermoacidophilic archaeon Sulfolobus solfataricus

• Published in: Microbiology (Society for General Microbiology) Vol. 158; no. Pt 6; pp. 1622 - 1633
• Main Authors: VÖLLMECKE, Christian, DREES, Steffen L, REIMANN, Julia, ALBERS, Sonja-Verena, LÜBBEN, Mathias
• Format: Journal Article
• Language: English
• Published: Reading Society for General Microbiology 01.06.2012
• Subjects: Adenosine Triphosphatases - genetics; Adenosine Triphosphatases - metabolism; Archaeal Proteins - genetics; Archaeal Proteins - metabolism; Bacteriology; Biological and medical sciences; Cation Transport Proteins - genetics; Cation Transport Proteins - metabolism; Copper - metabolism; Copper-Transporting ATPases; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Enzymologic; Microbiology; Miscellaneous; Molecular Sequence Data; Phylogeny; Reactive Oxygen Species - metabolism; Sulfolobus solfataricus - classification; Sulfolobus solfataricus - enzymology; Sulfolobus solfataricus - genetics; Sulfolobus solfataricus - metabolism; Acidophily; Enzyme; Archaeobacteria; Adenosinetriphosphatase; Thermophily; Sulfolobus solfataricus; Heavy metal; Resistance; Sulfolobaceae; Bacteria; Hydrolases; Sulfolobales; Copper
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.055905-0

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.