A new versatile peroxidase from Pleurotus

Lignin peroxidase (LiP) and manganese peroxidase (MnP) have been investigat ed in Phanerochaete chrysosporium. A third ligninolytic peroxidase has been described in Pleurotus and Bjerkandera. Two of these versatile peroxidases (VPs) have been cloned, sequenced and characterized. They have high affini ty for Mn2+, hydroquinones and dyes, and also oxidize veratryl alcohol, dim ethoxybenzene and lignin dimers. The deduced sequences show higher identity with Ph. chrysosporium LiP than MnP, but the molecular models obtained inc lude a Mn2+-binding site. Concerning aromatic substrate oxidation, Pl. eryn gii VP shows a putative long-range electron transfer pathway from an expose d trytophan to haem. Mutagenesis and chemical modification of this tryptoph an and the acidic residues forming the Mn2+-binding site confirmed their ro le in catalysis. The existence of several substrate oxidation sites is supp orted further by biochemical evidence. Residue conservation in other fungal peroxidases is discussed.