MetaCyc Enzyme: 2-nitrobenzoate nitroreductase

Gene: nbaA Accession Number: G-10159 (MetaCyc)

Species: Pseudomonas fluorescens KU-7

Subunit composition of 2-nitrobenzoate nitroreductase = [NbaA]2
         2-nitrobenzoate nitroreductase subunit = NbaA

The nbaA gene of Pseudomonas fluorescens KU-7, encoding a 2-nitrobenzoate nitroreductase has been cloned and expressed in Escherichia coli [Muraki03].

The specific activity of the recombinant enzyme, which was shown to be a homodimer, was measured in cell-free extracts of the heterologous host, and found to be 10 U/mg of protein.

The enzyme activity was augmented by the presence of a flavin (especially FMN) and a divalent metal ion (best results were obtained by adding 0.3 mM of Mn2+ and Fe2+, which increased activity by 89% and 66%, respectively).

Mutational analysis supported a role of Asn40, Asp76, and Glu113, which are predicted to form the binding site for a divalent metal ion implicated in FMN binding, and a role in NADPH binding for the 10-residue insertion in the β5-α2 loop [Iwaki07].

Molecular Weight of Polypeptide: 24.411 kD (from nucleotide sequence), 28.0 kD (experimental) [Iwaki07 ]

Molecular Weight of Multimer: 45.0 kD (experimental) [Iwaki07]

Unification Links: Protein Model Portal:A4UVY1 , UniProt:A4UVY1

Relationship Links: Entrez-Nucleotide:RELATED-TO:AB263093 , InterPro:IN-FAMILY:IPR002563 , InterPro:IN-FAMILY:IPR012349 , Pfam:IN-FAMILY:PF01613 , Smart:IN-FAMILY:SM00903

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Created 04-Sep-2007 by Caspi R , SRI International

Enzymatic reaction of: 2-nitrobenzoate nitroreductase

2-nitrobenzoate + 2 NADPH + 2 H+ <=> 2-hydroxylaminobenzoate + 2 NADP+ + H2O

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is favored in the direction shown.

In Pathways: 2-nitrobenzoate degradation I

Cofactors or Prosthetic Groups: FMN [Iwaki07]

Activators (Allosteric): Mn2+ [Iwaki07] , Fe2+ [Iwaki07]


Iwaki07: Iwaki H, Muraki T, Ishihara S, Hasegawa Y, Rankin KN, Sulea T, Boyd J, Lau PC (2007). "Characterization of a pseudomonad 2-nitrobenzoate nitroreductase and its catabolic pathway-associated 2-hydroxylaminobenzoate mutase and a chemoreceptor involved in 2-nitrobenzoate chemotaxis." J Bacteriol 189(9);3502-14. PMID: 17277060

Muraki03: Muraki T, Taki M, Hasegawa Y, Iwaki H, Lau PC (2003). "Prokaryotic homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase and 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase in the 2-nitrobenzoate degradation pathway of Pseudomonas fluorescens strain KU-7." Appl Environ Microbiol 69(3);1564-72. PMID: 12620844

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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