title: Differential regulation of manganese peroxidases and characterization of two variable MnP encoding genes in the white-rot fungus Physisporinus rivulosus.
abstract: Manganese peroxidase (MnP) production in the white-rot basidiomycete Physisporinus rivulosus T241i was studied. Separate MnP isoforms were produced in carbon-limited liquid media supplemented with Mn(2+), veratryl alcohol, or sawdust. The isoforms had different pH ranges for the oxidation of Mn(2+) and 2,6-dimethoxyphenol. Although lignin degradation by white-rot fungi is often triggered by nitrogen depletion, MnPs of P. rivulosus were efficiently produced also in the presence of high-nutrient nitrogen, especially in cultures supplemented with veratryl alcohol. Two MnP encoding genes, mnpA and mnpB, were identified, and their corresponding cDNAs were characterized. Structurally, the genes showed marked dissimilarity, and the expression of the two genes implicated quantitative variation and differential regulation in response to manganese, veratryl alcohol, or sawdust. The variability in regulation and properties of the isoforms may widen the operating range for efficient lignin degradation by P. rivulosus.
authors.affiliation: Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 56, Biocenter 1, 00014 Helsinki, Finland.
authors.forename: Terhi K
authors.initials: TK
authors.lastname: Hakala
authors.forename: Kristiina
authors.initials: K
authors.lastname: Hildén
authors.forename: Pekka
authors.initials: P
authors.lastname: Maijala
authors.forename: Cia
authors.initials: C
authors.lastname: Olsson
authors.forename: Annele
authors.initials: A
authors.lastname: Hatakka
mesh_terms: D000595:Amino Acid Sequence; D001592:Benzyl Alcohols / Q000378:metabolism; D003001:Cloning, Molecular; D003470:Culture Media; D018076:DNA, Complementary; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D020536:Enzyme Activators / Q000378:metabolism / Q000494:pharmacology; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000378:metabolism; D008345:Manganese / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000096:biosynthesis* / Q000235:genetics*; D020072:Polyporales / Q000201:enzymology* / Q000235:genetics; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D011748:Pyrogallol / Q000031:analogs & derivatives / Q000378:metabolism; D012331:RNA, Fungal / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D016415:Sequence Alignment; D014934:Wood / Q000378:metabolism
chemical_list: D001592:Benzyl Alcohols; D003470:Culture Media; D018076:DNA, Complementary; D004271:DNA, Fungal; D020536:Enzyme Activators; D005656:Fungal Proteins; D020033:Protein Isoforms; D012331:RNA, Fungal; D012333:RNA, Messenger; D011748:Pyrogallol; D008345:Manganese; C010120:pyrogallol 1,3-dimethyl ether; D008031:Lignin; D010544:Peroxidases; C051129:manganese peroxidase; C042197:veratryl alcohol