Figure 1.

(a) Prx1 catalytic cycle. The Prx1 peroxidase cycle and hyperoxidation mechanism are shown at the level of the Prx1 dimeric unit to highlight the conformational state [fully folded (FF) and locally unfolded (LU)] of the active site identified by the peroxidatic Cys C_P and C-terminal tail identified by resolving Cys C_R. The rate constants of peroxide reduction k_SOH, sulfinylation k_SO2, resolution k_SS, and FF–LU transition k_FF and k_LU are indicated. (b) Zoom into the catalytic site of Tsa1. The subunit containing the C_P is shown in blue, and the subunit containing the C_R is shown in yellow (PDB code 3SBC). Residues C_P and C_R are shown in yellow, W83 and W173 in orange, and W161 in red. Within the C-terminal tail, residues A177 and A178 are highlighted in green and the Y190-F191 motif in purple.