Catalytic subunit of protein phosphatase Z (PPZ) involved in iron assimilation (PubMed:25943523, PubMed:28753224). Regulates secondary metabolites production, including gliotoxin, pyripyropene A, fumagillin, fumiquinazoline A, triacetyl-fusarinine C, and helvolic acid (PubMed:25943523, PubMed:28753224). Plays a key role in pathogenicity (PubMed:28753224). H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 manganese ions per subunit. Interacts with at least 54 proteins, of which 31 are detected only after iron starvation and 22 are detected only in control conditions (PubMed:28753224). Only the regulatory subunit of the protein phosphatase PP1 (Afu1g04800/AFUB_005140) interacts with ppzA in both conditions (PubMed:28753224). Reduces sidC and sidG expression, slightly increases gliotoxin production, decreases growth in iron starvation conditions and leads to reduced conidiation at 44 degrees Celsius (PubMed:25943523). Reduces the production of pyripyropene A, fumagillin, fumiquinazoline A, triacetyl-fusarinine C, and helvolic acid (PubMed:28753224). Abolishes virulence in a neutropenic murine model of invasive pulmonary aspergillosis (PubMed:28753224). Belongs to the PPP phosphatase family. PP-Z subfamily.