Figure 2. Overall structure of the human PPA1 protein. A) The single domain monomeric structure. B) Superimposition of the monomeric structures of human PPA1 (magenta) and yeast PPase (blue, PDB code 1E6A). C) The dimeric structure of human PPA1 in two different viewing angles. The two monomers are colored cyan and magenta respectively. D) Electrostatic surface representation of the human PPA1 homodimeric structures. The surface areas are colored according to electrostatic potentials, from blue for the most positive, to white, to red for the most negative regions.