A novel gene, encoding 6-hydroxy-3-suceinoylpyridine hydroxylase, involved in nicotine degradation by Pseudomonas putida strain S16
A novel gene, encoding 6-hydroxy-3-suceinoylpyridine hydroxylase, involved in nicotine degradation by Pseudomonas putida strain S16
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编码 6-羟基-3-琥珀酰吡啶羟化酶的新基因参与恶臭假单胞菌 S16 菌株的尼古丁降解
DOI：
10.1128/aem.02529-07
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发表时间：
2008-03-01
影响因子：
4.4
通讯作者：
Xui, Ping
中科院分区：
文献类型：
--
作者：
Tang, Hongzhi;Wang, Shuning;Xui, Ping
先前的研究表明，假单胞菌可能以类似于哺乳动物代谢的方式攻击尼古丁的吡咯烷环，从而形成假烟碱，这是一种强效烟草特异性肺癌物质的直接前体。此外，假阴离子烟碱降解途径中的后续中间体6-羟基-3-琥珀酰吡啶（HSP）和2,5-二羟基吡啶（DHP）是两种重要的药物合成前体。然而，目前对吡咯烷途径降解尼古丁的分子机制知之甚少。在这项研究中，我们克隆并测序了一个4879 bp的与尼古丁降解有关的基因簇。中间产物n -甲基肌氨酸、假木烟碱、3-琥珀-壬基吡啶、热sp和DHP从含有该基因簇的转化细胞静息反应中鉴定出来，与野生型恶臭假单胞菌S16中报道的吡啶途径相同。对6-羟基-3-琥珀酰吡啶羟化酶（HSP羟化酶）基因进行克隆、测序并在大肠杆菌中表达，纯化得到的HSP羟化酶（38 kDa）依赖于NADH。对该936 bp片段的DNA序列分析表明，推导出的氨基酸与任何已知功能的蛋白质都没有相似性。
Previous research suggested that Pseudomonas spp. may attack the pyrrolidine ring of nicotine in a way similar to mammalian metabolism, resulting in the formation of pseudooxynicotine, the direct precursor of a potent tobacco-specific lung carcinogen. In addition, the subsequent intermediates, 6-hydroxy-3-succinoylpyridine (HSP) and 2,5-dihydroxypyridine (DHP) in the Pseudonionas nicotine degradation pathway are two important precursors for drug syntheses. However, there is little information on the molecular mechanism for nicotine degradation via the pyrrolidine pathway until now. In this study we cloned and sequenced a 4,879-bp gene cluster involved in nicotine degradation. Intermediates N-methy1myosmine, pseudooxynicotine, 3-succi-noylpyridine, HSP, and DHP were identified from resting cell reactions of the transformant containing the gene cluster and shown to be identical to those of the pyrrolidine pathway reported in wild-type strain Pseudomonas putida S16. The gene for 6-hydroxy-3-succinoylpyridine hydroxylase (HSP hydroxylase) catalyzing HSP directly to DHP was cloned, sequenced, and expressed in Escherichia coli, and the purified HSP hydroxylase (38 kDa) is NADH dependent. DNA sequence analysis of this 936-bp fragment reveals that the deduced amino acid shows no similarity with any protein of known function.