Figure 6.

Attenuation of TENGU function by a processing site mutation. A, Schematic representation of the TENGU-processing site mutant. The dark gray box indicates the secretion signal peptide. Light gray boxes indicate one of the N-terminal processing products predicted by in vitro processing analysis with symptom-inducing activities. White boxes indicate the C-terminal processing product. B, In vitro processing assay of the TENGU mutant. GST fusion proteins of wild-type TENGU (WT) and the 12AA13 TENGU mutant were incubated with plant extract or buffer and detected using gel electrophoresis followed by Coomassie Brilliant Blue staining. C, TOF-MS analysis of the 12AA13-GST-processing product. The sequence of the 12AA13 mutant is shown above the MS spectrum; the functional domain of TENGU is underlined; and mutated residues are shown in boldface. D, Symptom-inducing activities of TENGU and the 12AA13 mutant. E, Quantification of the symptom-inducing activity of the 12AA13 mutant.