title: Metabolism of 4-amino-3-hydroxybenzoic acid by Bordetella sp. strain 10d: A different modified meta-cleavage pathway for 2-aminophenols.
abstract: Bordetella sp. strain 10d metabolizes 4-amino-3-hydroxybenzoic acid via 2-hydroxymuconic 6-semialdehyde. Cell extracts from 4-amino-3-hydroxybenzoate-grown cells showed high NAD(+)-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(+) 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 via a dehydrogenative route, not via a hydrolytic route. This proposed metabolic pathway differs considerably from the modified meta-cleavage pathway of 2-aminophenol and those previously reported for methyl- and chloro-derivatives.
authors.affiliation: Division of Science of Biological Resources, Graduate School of Science and Technology, Kobe University, Rokko, Nada-ku, Kobe, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Orii
authors.forename: Shinji
authors.initials: S
authors.lastname: Takenaka
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Murakami
authors.forename: Kenji
authors.initials: K
authors.lastname: Aoki
mesh_terms: D010129:4-Aminobenzoic Acid / Q000737:chemistry / Q000378:metabolism; D000627:Aminophenols / Q000737:chemistry / Q000378:metabolism*; D001884:Bordetella / Q000737:chemistry / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism; D002457:Cell Extracts; D006836:Hydro-Lyases / Q000378:metabolism; D062385:Hydroxybenzoates / Q000737:chemistry / Q000378:metabolism*; D007535:Isomerases / Q000302:isolation & purification / Q000378:metabolism; D013058:Mass Spectrometry; D015394:Molecular Structure; D013057:Spectrum Analysis; D062366:para-Aminobenzoates
chemical_list: C489259:4-amino-3-hydroxybenzoic acid; D000627:Aminophenols; D002396:Catechols; D002457:Cell Extracts; D062385:Hydroxybenzoates; D062366:para-Aminobenzoates; C027667:2-aminophenol; D006836:Hydro-Lyases; C061677:2-oxopent-4-enoate hydratase; C021918:4-oxalocrotonate tautomerase; D007535:Isomerases; C034221:catechol; D010129:4-Aminobenzoic Acid