Fig. 6: PLCP inhibition by Avr2 is determined by four residues.
From: Evolution of a guarded decoy protease and its receptor in solanaceous plants
Substitution mutants of SpRcr3 (a), SlPip1 (b), SlRcr3 (c), and NbRcr3a-2 (d) were produced by agroinfiltration of N. benthamiana leaves. Apoplastic fluids were isolated at 2 dpi, preincubated for 45 min with or without 100 µM E-64, 2 µM Avr2 or Avr2Δ6, or DMSO, and labelled for 3 h with 2 µM MV201. Samples were separated on SDS-PAGE gels and scanned for fluorescence. e H148, R151, N194, and Q284 residues (magenta) locate around the substrate-binding groove in Rcr3. Homology model of SlRcr3 based on 1s4v10,68. Shown are the substrate-binding groove (dotted line), catalytic cysteine (yellow), and polymorphic residues between SpRcr3 and SlPip1 (orange). f Summary of the effect of variant residues on inhibition by Avr2, compared to residues present in SpRcr3. g Pepper Rcr3 (CaRcr3) substitutions enhance Avr2-triggered HR. h NbRcr3a-2 that carry substitutions enhancing inhibition by Avr2 without triggering HR. Mutant CaRcr3 or NbRcr3a-2 were transiently co-expressed with Cf-2 and Avr2 by agroinfiltration and pictures taken at 5 dpi.
