Fig. 2. Structure of PTPN13. (A) Full-length mouse PTPN13 and C-terminus Xenopus PTPN13. The full-length PTPN13 contains N-terminal FERM domain (also known as band 4.1 homology membrane-binding domain), five PDZ domains and a protein tyrosine phosphatase (PTPase) domain. (B) Alignment of predicted PTPN13 catalytic domain amino acid sequences of Xenopus (xPTPN13), and the sequences of mouse (mPTPN13) and human (hPTPN13). C terminus Xenopus PTPN13 is based on RT-PCR analysis, and the sequences are from databases (GenBank Accession Numbers BJ052929, BJ063819 and BJ070269). A solid line indicates the protein tyrosine phosphatase domain. An asterisk indicates the catalytically important residue in this domain that we used for mutagenesis in this report.