Structural Basis for the Function of the N-terminal Domain of the ATPase CopA from Bacillus subtilis

Abstract

The solution structure of the N-terminal region (151 amino acids) of a copper ATPase, CopA, from Bacillus subtilis, is reported here. It consists of two domains, CopAa and CopAb, linked by two amino acids. It is found that the two domains, which had already been separately characterized, interact one to the other through a hydrogen bond network and a few hydrophobic interactions, forming a single rigid body. The two metal binding sites are far from one another, and the short link between the domains prevents them from interacting. This and the surface electrostatic potential suggest that each domain receives copper from the copper chaperone, CopZ, independently and transfers it to the membrane binding site of CopA. The affinity constants of silver(I) and copper(I) are similar for the two sites as monitored by NMR. Because the present construct "domain-short link-domain" is shared also by the last two domains of the eukaryotic copper ATPases and several residues at the interface between the two domains are conserved, the conclusions of the present study have general validity for the understanding of the function of copper ATPases.

Functional and Biochemical Characterization of Cucumber Genes Encoding Two Copper ATPases CsHMA5.1 and CsHMA5.2

“…(51). In addition, the rate of CsHMA5.1-mediated and CsHMA5.2-mediated ATP hydrolysis was higher in the presence of Cu ϩ than upon addition of an equal concentration of Ag ϩ to the reaction media.…”

“…The phosphorylation of AtHMA6/PAA1 was also significantly (over 2-fold) higher in the presence of copper than in the presence of silver (12). In contrast, CopA from A. fulgidus was activated four times faster by Ag ϩ than by Cu ϩ (35), whereas CopA from B. subtilis was activated by both ions with similar efficiency (51). It has already been evidenced that copper ATPases from various organisms might behave similarly or differently with copper and silver.…”

Yeast Cox17 Solution Structure and Copper(I) Binding

“…Crystal and solution structures of Atx1 (50, 51), Atox1 (52), a bacterial homolog called CopZ (53,54), and domains of their target copper transport ATPases (55)(56)(57) reveal that the metal-binding site is located on a surface-exposed loop between the first ␤ strand and the first ␣ helix in the ␤␣␤␤␣␤ fold, with the first cysteine derived from the loop and the second cysteine derived from the N terminus of the helix. Similarly, the copper-binding site in Cox17 is located on a loop with the second coordinating cysteine at the N terminus of a helix (Fig.…”

Structure of human Wilson protein domains 5 and 6 and their interplay with domain 4 and the copper chaperone HAH1 in copper uptake

“…In coppertransporting P-type ATPases, the spatial arrangement of the two-domain WLN5-6 construct is evolutionarily conserved across phylogenetic boundaries from bacteria to yeast to man. A structurally characterized two-domain construct of CopA of Bacillus subtilis (31), denoted CopAab, has a shorter linker than WLN5-6 with a hydrogen-bonding network at the interdomain interface. Like WLN5-6, the metal-binding sites of CopAab are far from each other, and copper binding does not alter protein structure.…”