Scheme 2. Diagram of the T. maritima CopA reaction sequences indicating that the enzyme can be phosphorylated by ATP, or even by P_i in the absence of Cu⁺, yielding a phosphoenzyme species (E_b-P) undergoing very slow turnover.

The active enzyme conformation (E_a) undergoing fast turnover is only obtained following Cu⁺ binding to both NMBD and TMBS. Reproduced from [34] © 2009 American Chemical Society.