A novel peroxidase, oxidizing Mn 2 + and different aromatic compounds, was isolated. Hydroquinones, substituted phenols, dyes, other aromatic compounds and Mn 2 + were compared as reducing substrates, and conclusions presented in the light of a molecular model built by homology modeling. The enzymes showed the fastest reaction rates with Mn 2 + , but the highest affinity corresponded to hydroquinones and dyes. Oxidation of Reactive Black 5 (an azo-dye not oxidized by Mn 3 + ) was non-competitively inhibited by Mn 2 + . These findings, together with identification of putative Mn-binding site (involving Glu 3 6 , Glu 4 0 , Asp 1 7 5 and inner heme propionate) and long-range electron transfer pathways, indicate that different sites are involved in substrate oxidation.