Metabolism of 4-Amino-3-hydroxybenzoic Acid by Bordetella sp. Strain 10d : A Different Modified Meta-Cleavage Pathway for 2-Aminophenols
<I>Bordetella</I> sp. strain 10d metabolizes 4-amino-3-hydroxybenzoic acid <I>via</I> 2-hydroxymuconic 6-semialdehyde. Cell extracts from 4-amino-3-hydroxybenzoate-grown cells showed high NAD<SUP>+</SUP>-dependent 2-hydroxymuconic 6-semialdehyde dehydrogenase, 4-oxalocrotonate tautomerase, 4-oxalocrotonate decarboxylase, and 2-oxopent-4-enoate hydratase activities, but no 2-hydroxymuconic 6-semialdehyde hydrolase activity. These enzymes involved in 4-amino-3-hydroxybenzoate metabolism were purified and characterized. When 2-hydroxymuconic 6-semialdehyde was used as substrate in a reaction mixture containing NAD<SUP>+</SUP> and cell extracts from 4-amino-3-hydroxybenzoate-grown cells, 4-oxalocrotonic acid, 2-oxopent-4-enoic acid, and 4-hydroxy-2-oxovaleric acid were identified as intermediates, and pyruvic acid was identified as the final product. A complete pathway for the metabolism of 4-amino-3-hydroxybenzoic acid in strain 10d is proposed. Strain 10d metabolized 2-hydroxymuconic 6-semialdehyde derived from 4-amino-3-hydroxybenzoic acid <I>via</I> a dehydrogenative route, not <I>via</I> a hydrolytic route. This proposed metabolic pathway differs considerably from the modified <I>meta</I>-cleavage pathway of 2-aminophenol and those previously reported for methyl- and chloro-derivatives.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(11), 2653-2661, 2006-11-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry