FIGURE 2.

Role of linker 2 in substrate specificity in M. marinum ESX‐5. (a) Superimposition of T. curvata linker 2 (bright blue) and linker 3 (dark blue). The 43 residues that were not resolved in the crystal structure are indicated in red. (b) Schematic overview of M. marinum and M. tuberculosis EccC₅ as well as the chimeric constructs used to complement eccC₅ mutants of these species. See Figure S4a for the exchanged sequences. (c) Secretion analysis of M. marinum ∆eccC₅ complemented with WT eccC_5mmar, eccC_5mtub and chimeric constructs depicted in b. Proteins were visualized by SDS‐PAGE and immunoblotting using antibodies against EsxN and PE_PGRS proteins (ESX‐5 substrates), GroEL2 (lysis and whole‐cell loading control) and Ag85 (secreted fraction loading control)