Fig. 1.

A growing tyrosine phosphatase family. Tyr phosphatases are classified based on their nucleophilic catalytic residue (Cys, Asp, or His). The representative schematic depiction and domain composition of the members in each group is shown. Cys-based PTPs contain the signature motif CxxxxxR with 3 classes and 6 subclasses. SAC phosphoinositide phosphatases and PTP-like phytases (PTPLPs) (PALD1/paladin), sharing the PTP fold, have been included in the class I Cys-based group as subclasses III and IV. INPP4 phosphatases (subclass V) and TMEM55 phosphatases have been included in the class I Cys-based group as subclasses V and VI. SSU72 has been included here as part of this class II category of PTPs. Class III phosphatases remain as previously classified.¹³ Non-Cys based Tyr phosphatases include the eyes absent (EYA) phosphatases recognized as Asp-based phosphatases. For His-based phosphatases, the ubiquitin-associated (UBA) and Src homology 3 (SH3) domain-containing protein (UBASH3) PGM phosphatases and the acid phosphatases (ACPs) have been incorporated into the extended PTPomes. PTP protein tyrosine phosphatase domain, DSP dual-specificity phosphatase domain, SAC Sac phosphatase domain, AR arsenate reductase, Rhodanese rhodanese phosphatase domain, HAD-ED HAD EYA domain, PGM-HP PGM-like HP domain, Acid HP His acid phosphatase domain, Rhod-like rhodanese-like domain, SH2 Src homology 2 domain, SH3 Src homology 3 domain, FN fibronectin type 3 domain, NHR2 Nervy homology 2 domain, FERM FERM (4.1/ezrin/radixin/moesin) domain, PDZ PDZ (PSD-95/Dlg/ZO-1) domain, UBA ubiquitin-associated domain, Thrp Thr phosphatase region; 5-Phosphatase, 5-phosphoinositide phosphatase domain, C2 domain C2 (C2A-Copine) lipid-binding domain, Pro proline-rich, Gly glycosylated