Extended Data Fig. 1: Mapping and refolding of the NPR4 SBC.
From: Structural basis of salicylic acid perception by Arabidopsis NPR proteins
Related to Figs. 1, 2. a, Domain arrangements of A. thaliana NPR4 and different constructs used for mapping NPR4 SBC. b–f, Comparison of trypsin digestion profiles of truncated NPR4 proteins with or without 1 mM SA or 3-OH BA. Negative controls of limited proteolytic digestion of NPR4 were conducted with bovine serum albumin (BSA) (b), SA-insensitive NPR4(R419Q) mutant associated with npr4-4D (c) and NPR4(1–391) fragment (f). g, h, SA-dependent refolding of NPR4 SBC polypeptide affects its solubility. BA, benzoic acid, an inactive analogue of SA; Sup., supernatant; M, molecular weight marker. i, Superdex 75 size exclusion chromatography elution profile of the NPR4 SBC fragment refolded in the presence of SA. Excess SA was eluted after one column volume owing to a weak interaction with the resin. The inset shows the final purified NPR4 SBC fragment analysed by SDS–PAGE with Coomassie staining. Experiments in b–i were repeated three times or more with similar results.
