Cloning and sequencing of a 2,5-dichlorohydroquinone reductive dehalogenase gene whose product is involved in degradation of γ-hexachlorocyclohexane by Sphingomonas paucimobilis
Cloning and sequencing of a 2,5-dichlorohydroquinone reductive dehalogenase gene whose product is involved in degradation of γ-hexachlorocyclohexane by Sphingomonas paucimobilis
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DOI：
10.1128/jb.180.6.1354-1359.1998
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发表时间：
1998-03-01
影响因子：
3.2
通讯作者：
Takagi, M
中科院分区：
文献类型：
--
作者：
Miyauchi, K;Suh, SK;Takagi, M
少毛鞘氨醇单胞菌(Sphingomonas Paucimobilis UT26)利用卤代有机杀虫剂γ-六氯环己烷作为唯一的碳源和能源。在先前的研究中，我们克隆并鉴定了一个直接参与2，5-二氯苯二酚(2，5-DCHQ)降解的基因，命名为Lind。LIND基因编码343个氨基酸的多肽，与谷胱甘肽S转移酶家族的蛋白有较低的相似性。当LIND在大肠杆菌中大量表达时，经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳，Northern印迹分析表明，LIND基因在少见链霉菌UT26中的表达受到2，5-DCHQ的诱导表达，薄层层析和气相色谱-质谱仪分析表明，LIND能迅速地将2，5-DCHQ转化为氯氢醌(CHQ)，并将CHQ缓慢转化为氢醌。Lind是一种依赖谷胱甘肽的还原脱卤酶，参与了短链霉菌UT26对γ-六氯环己烷的降解。
Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole carbon and energy source, In a previous study, we showed that gamma-HCH is degraded to 2,5-dichlorohydroquinone (2,5-DCHQ) (Y. Nagata, R. Ohtomo, K. Miyauchi, M. Fukuda, K. Yano, and M. Takagi, J, Bacteriol, 176:3117-3125, 1994), In the present study, we cloned and characterized a gene, designated linD, directly involved in the degradation of 2,5-DCHQ. The linD gene encodes a peptide of 343 amino acids and has a low level of similarity to proteins which belong to the glutathione S-transferase family, When LinD was overproduced in Escherichia coli, a 40-kDa protein was found after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Northern blot analysis revealed that expression of the linD gene was induced by 2,5-DCHQ in S. paucimobilis UT26, Thin-layer chromatography and gas chromatography-mass spectrometry analyses with the LinD-overexpressing E. coli cells revealed that LinD converts 2,5-DCHQ rapidly to chlorohydroquinone (CHQ) and also converts CHQ slowly to hydroquinone. Lint) activity in crude cell extracts was increased 3.7-fold bg the addition of glutathione, All three of the Tn5-induced mutants of UT26, which lack 2,5-DCHQ dehalogenase activity, had rearrangements or a deletion in the linD region, These results indicate that LinD is a glutathione-dependent reductive dehalogenase involved in the degradation of gamma-HCH by S. paucimobilis UT26.