In vitro characterization of the homogalacturonan-binding domain of the wall-associated kinase WAK1 using site-directed mutagenesis

The extracellular domain of the wall-associated receptor kinase WAK1 from Arabidopsis thaliana was over-expressed, purified and tested for its ability to interact with calcium-associated homogalacturonans. Using receptor binding domain analysis, site-directed mutagenesis and interaction studies, we could identify specific amino acids involved in the binding of WAK1 to homogalacturonans.