Efficient Expression of a Phanerochaete chrysosporium

A manganese peroxidase gene (mnpl) from Phanerochaete chrysosporium was efficiently expressed in Aspergil-lus oryzae. Expression was achieved by fusing the mature cDNA of mnpl with the A. oryzae Taka amylase promoter and secretion signal. The 3 ' untranslated region of the glucoamylase gene of Aspergillus awamori provided the terminator. The recombinant protein (rMnP) was secreted in an active form, permitting rapid detection and purification. Physical and kinetic properties of rMnP were similar to those of the native protein. The A. oryzae expression system is well suited for both mechanistic and site-directed mutagenesis studies. The white rot basidiomycetes Phanerochaete chrysosporium has served as a model system for investigations of lignin and organopollutant degradation (1, 9, 10, 13). System components include the H202-generating enzyme glyoxal oxidase, lignin peroxidases (LIPs), and manganese peroxidases (MnPs). MnPs are heme protein peroxidases which catalyze the I-1202-depen-dent oxidation of Mn2+ (12, 24). MnP is oxidized by H202 by two electrons to generate an intermediate known as compound I. Compound I can oxidize Mn2+ to Mn3+ or can oxidiz