Catabolic role of a three-component salicylate oxygenase from Sphingomonas yanoikuyae B1 in polycyclic aromatic hydrocarbon degradation
Catabolic role of a three-component salicylate oxygenase from Sphingomonas yanoikuyae B1 in polycyclic aromatic hydrocarbon degradation
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DOI：
10.1016/j.bbrc.2004.12.060
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发表时间：
2005-02-18
影响因子：
3.1
通讯作者：
Kim, E
中科院分区：
文献类型：
--
作者：
Cho, OY;Choi, KY;Kim, E
Sphingomonas yanoikuyae B1 拥有几种不同的多组分加氧酶，参与芳香族化合物的代谢。先前已在参与单环和多环芳烃降解的基因簇中鉴定了编码加氧酶铁硫蛋白组分的大小亚基的六对不同基因。加氧酶大亚基基因 bphA1c 之一的插入失活会导致突变菌株无法在萘、菲或水杨酸盐上生长。敲除突变体从萘中积累水杨酸，从菲中积累1-羟基-2-萘酸，表明水杨酸加氧酶活性丧失。互补实验证实 S. yanoikuyae B1 中的水杨酸加氧酶是一种三组分酶，由 bph A2cA1c 编码的加氧酶、相邻 bphA3 编码的铁氧还蛋白和距离超过 25 kb 的 bphA4 编码的铁氧还蛋白还原酶组成。 bphA3-bphA2c-bphA1c 基因在大肠杆菌中的表达证明了水杨酸加氧酶将水杨酸转化为儿茶酚以及将 3-、4-和 5-甲基水杨酸转化为甲基儿茶酚的能力。 (C) 2004 Elsevier Inc. 保留所有权利。
Sphingomonas yanoikuyae B1 possesses several different multicomponent oxygenases involved in metabolizing aromatic compounds. Six different pairs of genes encoding large and small subunits of oxygenase iron-sulfur protein components have previously been identified in a gene cluster involved in the degradation of both monocyclic and polycyclic aromatic hydrocarbons. Insertional inactivation of one of the oxygenase large subunit genes, bphA1c, results in a mutant strain unable to grow on naphthalene, phenanthrene, or salicylate. The knockout mutant accumulates salicylate from naphthalene and 1-hydroxy-2-naphthoic acid from phenanthrene indicating the loss of salicylate oxygenase activity. Complementation experiments verify that the salicylate oxygenase in S. yanoikuyae B1 is a three-component enzyme consisting of an oxygenase encoded by bph A2cA1c, a ferredoxin encoded by the adjacent bphA3, and a ferredoxin reductase encoded by bphA4 located over 25 kb away. Expression of bphA3-bphA2c-bphA1c genes in Escherichia coli demonstrated the ability of salicylate oxygenase to convert salicylate to catechol and 3-, 4-, and 5-methylsalicylate to methylcatechols. (C) 2004 Elsevier Inc. All rights reserved.