Phosphotyrosine protein phosphatase I (IPR023485) is a protein phosphatase that works only on tyrosine. It uses a cysteine phosphatase intermediate to remove phosphate groups from tyrosine residues. It is crucial in the regulation of cell growth, proliferation, differentiation, and transformation. The PTPase domain, centered on the active site cysteine, characterizes tyrosine-specific protein phosphatases (IPR000387). Furthermore, studies have demonstrated the significance of certain conserved residues in the vicinity. A part of tensin and tensin-like proteins called lipid phosphatase domain is structurally similar to tyrosine-protein phosphatase (IPR029021). This includes cyclin G-associated kinase (GAK) and phosphoinositide phosphatase PTEN (phosphatase and tensin homolog).