Low molecular weight PTPase

The PTPases share the signature motif (H/V)C(X)5R(S/T). This motif is also found in the low-molecular-weight PTPases, as well as in the VH 1-like dual-specific phosphatases, so-called because they dephosphorylate phosphotyrosine as well as phospho-Ser/Thr residues.129,149 These three groups of phosphatases have little sequence similarity other than the signature motif and the placement of the essential Cys and Arg residues in the active site. 

The X-ray structures of a number of PTPases have been reported, including the catalytic domains of PTP1B complexed with tungstate150 and of Yop51 from Yersinia (residues 163-468)151 with and without complexed tungstate. The structure of the human dual-specific phosphatase VHR (Vaccina HI-related) has also been determined,152 as well as those of several low-molecular-weight PTPases, including... 

Table 3 Kinetic isotope effects for reactions of pNPP with members of the PTPase family the Yersinia PTPase (YopH), PTP1, the dual-specific VHR, and the low-molecular-weight PTPase Stpl...

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