Fig. 3.

The N‐terminal α1 helix is critical for autoactivity. (a) Alignment of the N‐terminal region of CC^A309 and CC^A10‐1. Different residues are highlighted in green. (b) Schematic diagram of N‐terminal chimeras between CC^A309 and CC^A10‐1. (c) Cell death induced by the CC^A309 and CC^A10‐1 mutants described in (b). (d) Compromised cell death associated with defective α1 helix in Pvr4 and the CC domain of Pvr4 (CC_Pvr4). Phytophthora sojae necrosis‐inducing protein (NIP) was used as a positive control for cell death. All swap and point mutants were transiently expressed in Nicotiana benthamiana, and cell death was visualized after 3 d post infiltration (dpi). (e, f) Protein accumulation as described in (d) was investigated using Western blotting analysis. Equal protein loading was confirmed by staining membranes with Ponceau S. The above experiments were repeated at least three times with similar results.