Fig. 2

Classification of PTPs in the human genome. There are ~126 PTPs in the human genome. These PTPs are classified into three major groups based on their nucleophilic catalytic residue (Cys, Asp, or His) and topology. The numbers in parentheses indicate the members of PTPs included in each group. Only 9 PTPs are Asp- or His-based; the remaining 117 are Cys-based PTPs consisting of classes I, II, and III. Class I PTPs are further divided into six groups based on domain architecture and the degree of homology between catalytic domains. Classes II and III contain only two and three members, respectively. EYA eyes absent, UBASH3 ubiquitin-associated and SH3 domain-containing protein, ACP acid phosphatase, VH1 Vaccinia virus H1 gene product, DUSP dual-specificity phosphatase, RPTP receptor-like protein tyrosine phosphatase, NRPTP nonreceptor protein tyrosine phosphatase; MKP mitogen-activated protein kinase phosphatase, PRL phosphatase of regenerating liver, CDC cell division cycle, PTEN phosphatase and tensin homolog, MTM myotubularin, SAC sac phosphoinositide phosphatase, PALD1 phosphatase domain-containing paladin 1, INPP4 inositol polyphosphate-4-phosphatase, LMW low molecular weight, SSU72 RNA polymerase II subunit A C-terminal domain phosphatase SSU72