Gibello A, Ferrer E, Sanz J, Martin M
Departamento de Microbiología (Patología Animal I), Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
Appl Environ Microbiol. 1995 Dec;61(12):4167-71. doi: 10.1128/aem.61.12.4167-4171.1995.
The expression of Klebsiella pneumoniae hpaA and hpaH genes, which code for 4-hydroxyphenylacetic acid hydroxylase in Escherichia coli K-12 derivative strains, is associated with the production of a dark brown pigment in the cultures. This pigment has been identified as a polymer which shows several of the characteristics reported for microbial melanins and results from the oxidative activity of 4-hydroxyphenylacetic acid hydroxylase on some dihydroxylated compounds to form o-quinones. A dibenzoquinone is formed from the oxidation of different mono- or dihydroxylated aromatic compounds by the enzyme prior to polymerization. We report a hydroxylase activity, other than tyrosinase, that is associated with the synthesis of a bacterial melanin.
肺炎克雷伯菌hpaA和hpaH基因在大肠杆菌K-12衍生菌株中编码4-羟基苯乙酸羟化酶,其表达与培养物中深棕色色素的产生有关。这种色素已被鉴定为一种聚合物,它具有一些已报道的微生物黑色素的特征,是4-羟基苯乙酸羟化酶对一些二羟基化化合物进行氧化活性以形成邻醌的结果。在聚合之前,该酶通过氧化不同的单羟基或二羟基化芳香化合物形成二苯醌。我们报道了一种除酪氨酸酶外与细菌黑色素合成相关的羟化酶活性。