Fig. 5. P69B is an effector hub targeted by five pathogen-derived inhibitors.

AFM-predicted models of P69B without inhibitor (a), or with XpSsp1; (b) CfEcp36; (c) FoTIL; (d) FoSix15 (e) and PiEpi1 (f). P69B is shown in a gray surface representation with the hyper-variant residue (crème) and the active site (red), in the substrate binding groove that has substrate binding pockets (S4-S2-S1-S2’) that bind to substrate/inhibitor residues P4, P2, P1 and P2’, respectively. The inhibitors are shown as cartoons and sticks and colored using a rainbow scheme based on their plDDT scores, which range from 0 (worst) to 100 (best). The zoomed image (bottom) shows the predicted occupation of the substrate binding pockets in P69B by different residues of the inhibitor. g Sequence conservation between homologs of the identified P69B inhibitors. Shown is the sequence logo for n = x close homologs from other plant pathogen species, identified by BLAST searches in the NCBI database and presented in Weblogo⁹⁵. Highlighted are the residues that probably interact with the substrate binding pockets in P69B (circles); the conserved Asp residue in CfEcp36 that interacts with the catalytic site (blue); the residues that might interact with the variant residue in P69B (arrows); and putative disulfide brides observed in the AFM model (gray lines). PDB files for the shown models are available in Supplementary Data 3.