Branching of o-nitrobenzoate degradation pathway in Arthrobacter protophormiae RKJ100: identification of new intermediates.
We have earlier reported a novel reductive pathway for o-nitrobenzoate (ONB) degradation (at 0.5 mM) in Arthrobacter protophormiae RKJ100, which proceeds via the formation of o-hydroxylaminobenzoate (HABA) and anthranilate (AA). During growth of this organism at 40 times higher concentration (20 mM) of ONB, 3-hydroxyanthranilate (HAA) was identified as an intermediate by thin layer chromatography, gas chromatography and high performance liquid chromatography studies. Crude cell extracts of ONB-grown cells showed HAA 3,4-dioxygenase activity suggesting HAA as a terminal aromatic intermediate of the catabolic energy-yielding pathway as shown before in Pseudomonas fluorescens strain KU-7. HAA is further cleaved to 2-amino-3-carboxymuconic-6-semialdehyde by the action of HAA 3,4-dioxygenase. In this report we propose that ONB degradation occurs via the formation of HABA and the pathway branches at this point to form the two different aromatic intermediates AA and HAA by the action of a reductase and a mutase, respectively.
Pandey
Gunjan
G
Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India.
Paul
Debarati
D
Jain
Rakesh K
RK
D015095:3-Hydroxyanthranilic Acid / Q000378:metabolism; D001173:Arthrobacter / Q000378:metabolism*; D001391:Azo Compounds / Q000378:metabolism; D001673:Biodegradation, Environmental; D019751:Intramolecular Transferases / Q000378:metabolism; D009579:Nitrobenzoates / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism; D013379:Substrate Specificity
D001391:Azo Compounds; D009579:Nitrobenzoates; C001413:HABA; D015095:3-Hydroxyanthranilic Acid; D010088:Oxidoreductases; D019751:Intramolecular Transferases