The substrate specificity of aniline dioxygenase is mainly determined by two of its components: glutamine synthetase-like enzyme and oxygenase
The substrate specificity of aniline dioxygenase is mainly determined by two of its components: glutamine synthetase-like enzyme and oxygenase
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苯胺双加氧酶的底物特异性主要由其两个组分决定：类谷氨酰胺合成酶和加氧酶
DOI：
10.1007/s00253-019-09871-3
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发表时间：
2019-05
影响因子：
5
通讯作者：
Yan Xin
中科院分区：
文献类型：
--
作者：
Ji Junbin;Zhang Ji;Liu Yongchuang;Zhang Yanting;Liu Yuanxin;Yan Xin
苯胺及其衍生物的残留是严重的环境污染物。苯胺双加氧酶（AD）来源于好氧菌，可催化苯胺转化为邻苯二酚，在芳香胺的生物修复和生物精炼过程中具有潜在的应用价值。AD含有四种组分：谷氨酰胺合成酶（GS）样酶、谷氨酰胺转移酶（GAT）样酶、加氧酶和还原酶。来自不同宿主的AD对苯胺衍生物表现出不同的底物特异性。然而，AD的什么组分决定AD的底物特异性仍然是未知的，这限制了通过诱变扩展AD的底物谱的效果。在此，异源表达并纯化了具有不同底物范围的两种AD（AtdA 1A 2A 3A 4A 5和Δ QTA 1A 2B）的每种组分。使用纯化的组分在体外成功地构建了两种AD的活性。为了鉴定影响AD底物特异性的组分，研究了各组分的底物特异性。AtdA 1A 2A 3A 4A 5不能催化4-甲基苯胺与GS-样酶AtdA 1确定;其不能转化2-异丙基苯胺是由加氧酶组分引起的，其不能转化4-异丙基苯胺是由GS-样酶AtdA 1和加氧酶组分引起的。GS-like enzyme GS-Q决定了GS-QA 1A 2B不能催化2-甲基苯胺; GS-like enzyme GS-Q和加氧酶组分都能导致GS-QA 1A 2B不能转化2-异丙基苯胺。总之，这些结果表明GS样酶和加氧酶而不是GAT样酶或还原酶在AD的底物特异性中起主导作用，并且这一发现将促进AD的工程化以扩大其底物范围。
The residues of aniline and its derivatives are serious environment pollutants. Aniline dioxygenase (AD) derived from aerobic bacteria catalyzes the conversion of aniline to catechol, which has potential use in the bioremediation of aromatic amines and biorefining process. AD contains four components: a glutamine synthetase (GS)-like enzyme, a glutamine amidotransferase (GAT)-like enzyme, oxygenase, and reductase. ADs from diverse hosts exhibit different substrate specificities against aniline derivatives. However, what component of AD determines AD’s substrate specificity is still unknown which limits the effects of extending AD’s substrate spectrum through mutagenesis. Here, each component of two ADs (AtdA1A2A3A4A5 and AdoQTA1A2B) which have different substrate ranges was heterologously expressed and purified. The activity of both ADs was successfully constructed in vitro using the purified components. To identify the component that affects the substrate specificity of the ADs, the substrate specificity of each component was studied. The inability of AtdA1A2A3A4A5 to catalyze 4-methylaniline was determined with GS-like enzyme AtdA1; its inability to convert 2-isopropylaniline was caused by the oxygenase component, and its inability to convert 4-isopropylaniline was caused by both GS-like enzyme AtdA1 and oxygenase components. The inability of AdoQTA1A2B to catalyze 2-methylaniline was determined by GS-like enzyme AdoQ; its inability to convert 2-isopropylaniline was caused by both GS-like enzyme AdoQ and oxygenase components. Together, these results show that GS-like enzyme and oxygenase but not GAT-like enzyme or reductase play dominant roles in the substrate specificity of AD, and this finding will facilitate the engineering of AD to expand its substrate range.
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DOI：
10.1080/10934520701629674
发表时间：
2007-11
期刊：
Journal of Environmental Science and Health, Part A
影响因子：
--
作者：
Rensheng Zhuang;W. Zhong;Jun Yao;Huilun Chen;Lin Tian;Yong Zhou;Fei Wang;E. Bramanti;G. Záray
通讯作者：
Rensheng Zhuang;W. Zhong;Jun Yao;Huilun Chen;Lin Tian;Yong Zhou;Fei Wang;E. Bramanti;G. Záray
影响因子：
5.8
作者：
Shujuan Wang;K. Poon;Z. Cai
通讯作者：
Shujuan Wang;K. Poon;Z. Cai
影响因子：
4.4
作者：
Krol, J. E.;Penrod, J. T.;Top, E. M.
通讯作者：
Top, E. M.
影响因子：
1.6
作者：
Nam, JW;Nojiri, H;Omori, T
通讯作者：
Omori, T
影响因子：
3.2
作者：
Fukumori, F;Saint, CP
通讯作者：
Saint, CP