Ligninase and other manganese-dependent fungal peroxidases.
Ligninases and related extracellular fungal peroxidases belong to class II of the plant heme-dependent peroxidase superfamily. All members of the superfamily share a heme prosthetic group and catalyze a multistep oxidative reaction involving hydrogen peroxide as the electron acceptor. Class II peroxidases are fungal glycoproteins that have been implicated in the oxidative breakdown of lignin, the main cell wall component of woody plants. They contain four conserved disulphide bridges and two conserved calcium binding sites.