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Biochemical and molecular characterization of an atypical manganese peroxidase of the litter-decomposing fungus Agrocybe praecox.
Hildén, Kristiina; Mäkelä, Miia R; Steffen, Kari T; Hofrichter, Martin; Hatakka, Annele; Archer, David B; Lundell, Taina K.
Afiliação
  • Hildén K; Department of Food and Environmental Sciences, Viikki Biocenter, University of Helsinki, Finland; School of Biology, University of Nottingham, UK. Electronic address: kristiina.s.hilden@helsinki.fi.
  • Mäkelä MR; Department of Food and Environmental Sciences, Viikki Biocenter, University of Helsinki, Finland.
  • Steffen KT; Department of Food and Environmental Sciences, Viikki Biocenter, University of Helsinki, Finland.
  • Hofrichter M; Department of Bio- and Environmental Sciences, International Graduate School of Zittau, Germany.
  • Hatakka A; Department of Food and Environmental Sciences, Viikki Biocenter, University of Helsinki, Finland.
  • Archer DB; School of Biology, University of Nottingham, UK.
  • Lundell TK; Department of Food and Environmental Sciences, Viikki Biocenter, University of Helsinki, Finland.
Fungal Genet Biol ; 72: 131-136, 2014 Nov.
Article em En | MEDLINE | ID: mdl-24657475
Agrocybe praecox is a litter-decomposing Basidiomycota species of the order Agaricales, and is frequently found in forests and open woodlands. A. praecox grows in leaf-litter and the upper soil and is able to colonize bark mulch and wood chips. It produces extracellular manganese peroxidase (MnP) activities and mineralizes synthetic lignin. In this study, the A. praecox MnP1 isozyme was purified, cloned and enzymatically characterized. The enzyme catalysed the oxidation of Mn(2+) to Mn(3+), which is the specific reaction for manganese-dependent class II heme-peroxidases, in the presence of malonate as chelator with an activity maximum at pH 4.5; detectable activity was observed even at pH 7.0. The coding sequence of the mnp1 gene demonstrates a short-type of MnP protein with a slightly modified Mn(2+) binding site. Thus, A. praecox MnP1 may represent a novel group of atypical short-MnP enzymes. In lignocellulose-containing cultures composed of cereal bran or forest litter, transcription of mnp1 gene was followed by quantitative real-time RT-PCR. On spruce needle litter, mnp1 expression was more abundant than on leaf litter after three weeks cultivation. However, the expression was constitutive in wheat and rye bran cultures. Our data show that the atypical MnP of A. praecox is able to catalyse Mn(2+) oxidation, which suggests its involvement in lignocellulose decay by this litter-decomposer.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Peroxidases / Agrocybe Idioma: En Ano de publicação: 2014 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Peroxidases / Agrocybe Idioma: En Ano de publicação: 2014 Tipo de documento: Article