Figure 3.

Protein phosphatase assays of GST-MpABI1 fusion proteins. A, Mg²⁺- and Mn²⁺-dependent activities of GST-MpABI1 toward the ³²P-labeled MBP. B, Schematic representation of various GST-MpABI1 constructs used for protein phosphatase assays. C, SDS-PAGE of GST fusion proteins of MpABI1 and its mutant proteins. The proteins were stained with Coomassie Brilliant Blue after electrophoresis. Positions of the molecular mass markers are shown on the left. Lane 1, GST-MpABI1; lane 2, GST-MpABI1-d1; lane 3, GST-MpABI1-d2; lane 4, GST-MpABI1-G298D. D, Protein phosphatase activity of wild-type and mutant GST fusion proteins of MpABI1 toward the ³²P-labeled MBP (n = 3). Phosphatase reactions were carried out at 30°C for 10 min and terminated by the addition of TCA. Activity is represented as a percentage of [³²P]orthophosphate released by GST-MpABI1 in the presence of 5 mm Mg²⁺.