FIGURE 1.

Identification of the CaM-binding domain of AtMKP1. A, schematic representation of AtMKP1 (D0) and serial fragment constructs (D1–D8). The putative CaM-binding domain (CaMBD) is represented by a black box, whereas the catalytic domain and gelsolin domain are represented by a gray box. Amino acid positions of each fragment are indicated. D0–D8 represent GST fusion constructs containing the specified fragments of AtMKP1. The CaM-binding ability is specified as + (CaM binding) or – (no CaM binding). B, CaM binding overlay analysis. GST and GST fusion proteins of serial fragment mutants (D0–D8) of AtMKP1 were expressed in E. coli. Recombinant proteins were analyzed by Western blotting with an anti-GST antibody (Western). The CaM:HRP overlay assay was performed using ACaM2:HRP in the presence of 1 mm CaCl₂ or 5 mm EGTA.