論文

査読有り
2020年6月18日

Molecular Cloning and Heterologous Expression of Manganese(II)-Oxidizing Enzyme from Acremonium strictum Strain KR21-2

Catalysts
  • Fuyumi Tojo
  • ,
  • Ayumi Kitayama
  • ,
  • Naoyuki Miyata
  • ,
  • Kunihiro Okano
  • ,
  • Jun Fukushima
  • ,
  • Ryuichiro Suzuki
  • ,
  • Yukinori Tani

10
6
開始ページ
686
終了ページ
686
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.3390/catal10060686
出版者・発行元
MDPI AG

Diverse ascomycete fungi oxidize manganese(II) [Mn(II)] and produce Mn(III, IV) oxides in terrestrial and freshwater environments. Although multicopper oxidase (MCO) is considered to be a key catalyst in mediating Mn(II) oxidation in ascomycetes, the responsible gene and its product have not been identified. In this study, a gene, named mco1, encoding Mn(II)-oxidizing MCO from Acremonium strictum strain KR21-2 was cloned and heterologously expressed in the methylotrophic yeast Pichia pastoris. Based on the phylogenetic relationship, similarity of putative copper-binding motifs, and homology modeling, the gene product Mco1 was assigned to a bilirubin oxidase. Mature Mco1 was predicted to be composed of 565 amino acids with a molecular mass of 64.0 kDa. The recombinant enzyme oxidized Mn(II) to yield spherical Mn oxides, several micrometers in diameter. Zinc(II) ions added to the reaction mixture were incorporated by the Mn oxides at a Zn/Mn molar ratio of 0.36. The results suggested that Mco1 facilitates the growth of the micrometer-sized Mn oxides and affects metal sequestration through Mn(II) oxidation. This is the first report on heterologous expression and identification of the Mn(II) oxidase enzyme in Mn(II)-oxidizing ascomycetes. The cell-free, homogenous catalytic system with recombinant Mco1 could be useful for understanding Mn biomineralization by ascomycetes and the sequestration of metal ions in the environment

リンク情報
DOI
https://doi.org/10.3390/catal10060686
URL
https://www.mdpi.com/2073-4344/10/6/686/pdf
ID情報
  • DOI : 10.3390/catal10060686
  • eISSN : 2073-4344

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