Inonotus obliquus is a pathogenic fungus found in living trees and has been widely used as a
traditional medicine for
cancer therapy. Although
lignocellulose-degrading
enzymes are involved in the early stages of host
infection, the parasitic life cycle of this fungus has not been fully understood. In this study, we aimed to investigate the activities of
laccase (Lac),
manganese peroxidase (MnP), and
lignin peroxidase (LiP) from I. obliquus cultivated in Kirk's medium. The fungus was subjected to genome sequencing, and genes related to wood degradation were identified. The draft genome sequence of this fungus comprised 21,203 predicted
protein-coding genes, of which 134 were estimated to be related to wood degradation. Among these, 47 genes associated with
lignin degradation were found to have the highest number of mnp genes. Furthermore, we cloned the
cDNA encoding a putative MnP, referred to as IoMnP1, and characterized its molecular structure. The results show that IoMnP1 has catalytic properties analogous to MnP. Phylogenetic analysis also confirmed that IoMnP1 was closely related to the MnPs from Pyrrhoderma noxium, Fomitiporia mediterranea, and Sanghuangporus baumii, which belong to the same family of Hymenochaetaceae. From the above results, we suggest that IoMnP1 is a member of MnPs.