title: Distinct functions of serial metal-binding domains in the Escherichia coli P1 B -ATPase CopA.
abstract: P1 B -ATPases are among the most common resistance factors to metal-induced stress. Belonging to the superfamily of P-type ATPases, they are capable of exporting transition metal ions at the expense of adenosine triphosphate (ATP) hydrolysis. P1 B -ATPases share a conserved structure of three cytoplasmic domains linked by a transmembrane domain. In addition, they possess a unique class of domains located at the N-terminus. In bacteria, these domains are primarily associated with metal binding and either occur individually or as serial copies of each other. Within this study, the roles of the two adjacent metal-binding domains (MBDs) of CopA, the copper export ATPase of Escherichia coli were investigated. From biochemical and physiological data, we deciphered the protein-internal pathway of copper and demonstrate the distal N-terminal MBD to possess a function analogous to the metallochaperones of related prokaryotic copper resistance systems, that is its involvement in the copper transfer to the membrane-integral ion-binding sites of CopA. In contrast, the proximal domain MBD2 has a regulatory role by suppressing the catalytic activity of CopA in absence of copper. Furthermore, we propose a general functional divergence of tandem MBDs in P1 B -ATPases, which is governed by the length of the inter-domain linker.
authors.affiliation: Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany.
authors.forename: Steffen L
authors.initials: SL
authors.lastname: Drees
authors.affiliation: Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany.
authors.forename: Dominik F
authors.initials: DF
authors.lastname: Beyer
authors.affiliation: Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Lenders-Lomscher
authors.affiliation: Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Lübben
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001665:Binding Sites; D027682:Cation Transport Proteins / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D008954:Models, Biological; D008958:Models, Molecular; D017434:Protein Structure, Tertiary
chemical_list: D027682:Cation Transport Proteins; D029968:Escherichia coli Proteins; D003300:Copper; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases; C000612460:copA protein, E coli