Biological Nitrogen Removal Database

Fusarium oxysporum strain MT-811 (JCM11502)

• Phylum : Ascomycota
• Class : Sordariomycetes
• Order : Hypocreales
• Family : Nectriaceae
• Genus : Fusarium

Soil

copper-containing nitrite reductase 

• Encoding Gene:NirK
• DNA Size：1885 bp
• Nucleotide FASTA sequence： Link

• UniProt I.D: A9XR52

• Pro_GenBank I.D： ABU88100.1

• Length：496 aa
• Protein FASTA_sequence: Link

• Reference：Kim et al., 2009
• Title：Eukaryotic nirK Genes Encoding Copper-Containing Nitrite Reductase: Originating from the Protomitochondrion?
• Pubmed ID：19270125.0
• Pubmed link： Link

• Full research link： Link

• Abstract：Although denitrification or nitrate respiration has been found among a few eukaryotes, its phylogenetic relationship with the bacterial system remains unclear because orthologous genes involved in the bacterial denitrification system were not identified in these eukaryotes. In this study, we isolated a gene from the denitrifying fungus Fusarium oxysporum that is homologous to the bacterial nirK gene responsible for encoding copper-containing nitrite reductase (NirK). Characterization of the gene and its recombinant protein showed that the fungal nirK gene is the first eukaryotic ortholog of the bacterial counterpart involved in denitrification. Additionally, recent genome analyses have revealed the occurrence of nirK homologs in many fungi and protozoa, although the denitrifying activity of these eukaryotes has never been examined. These eukaryotic homolog genes, together with the fungal nirK gene of F. oxysporum, are grouped in the same branch of the phylogenetic tree as the nirK genes of bacteria, archaea, and eukaryotes, implying that eukaryotic nirK and its homologs evolved from a single ancestor (possibly the protomitochondrion). These results show that the fungal denitrifying system has the same origin as its bacterial counterpart.