※ TULA-2 family introduction

    TULA/STS contain two members, UBASH3A/TULA-1 and UBASH3B/TULA-2. Sequence analysis show that they share a conserved multidomain structure, they contain an N-terminal ubiquitin-association domain, followed by a Src-homology 3 domain, and a C-terminal phosphatase domain. TULA/STS show tyrosine phosphatase activity toward para-nitrophenyl phosphate, phosphotyrosine peptides and phosphoprotein ZAP70, Syk and certain Src family members. TULA/STS are distinct from other PTP which use a cysteine residue as a catalytic residue, TULA/STS utilize a "D" to catalyze the dephosphorylation. TULA/STS show some sequence similarity with histidine phosphatase superfamily (1).

Reference
1. Chen, X., Ren, L., Kim, S., Carpino, N., Daniel, J.L., Kunapuli, S.P., Tsygankov, A.Y. and Pei, D. (2010) Determination of the substrate specificity of protein-tyrosine phosphatase TULA-2 and identification of Syk as a TULA-2 substrate. J Biol Chem, 285, 31268-31276. PMID: 20670933