Fig. 5.

Reversal of protein S-mycothiolation by the mycoredoxin-1 pathway. (A) In MSH-producing Actinomycetes, S-mycothiolated proteins are reduced by mycoredoxin-1 (Mrx1), resulting in an Mrx1-SSM intermediate that is reduced by MSH leading to MSSM. The NADPH-dependent mycothiol disulfide reductase Mtr recycles MSSM back to MSH. (B) The crystal structure of the reduced Mrx1 (PDB ID: 2LQO) and (C) its active site. (D) The oxidized Mrx1 active site in its intramolecular disulfide form (PDB ID: 2LQQ). The active and resolving Cys residues of Mrx1 are shown as spheres in (B) and as sticks in (C, D).