Biosynthesis of 3-methoxy-5-methyl naphthoic acid and its incorporation into the antitumor antibiotic azinomycin B
Biosynthesis of 3-methoxy-5-methyl naphthoic acid and its incorporation into the antitumor antibiotic azinomycin B
复制标题
3-甲氧基-5-甲基萘甲酸的生物合成及其与抗肿瘤抗生素阿齐霉素 B 的结合。
DOI：
10.1039/b926358f
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发表时间：
2010-01-01
影响因子：
--
通讯作者：
Liu, Wen
中科院分区：
文献类型：
--
作者：
Ding, Wei;Deng, Wei;Liu, Wen
Azinomycin B是一种有效的抗肿瘤抗生素，具有一组不寻常的，密集组装的功能。其中，3-甲氧基-5-甲基萘甲酸（NPA）部分提供了一个重要的非共价缔合与DNA，并可能，因此，有助于特异性的DNA烷基化的生物活性的展览。我们以前克隆和测序的azinomycin B生物合成基因簇，并提出四种酶：AziB B，AziB 1，AziB 2，和AziA 1，参与萘甲酸部分的形成和掺入。在这项研究中，我们报告在体内和/或体外表征的P450羟化酶AziB 1，O-甲基转移酶AziB 2，和底物特异性的非核糖体肽合成酶（NRPS）AziA 1，提供洞察到个别步骤的时间在后期修改的5-甲基-NPA合成的迭代I型聚酮合成酶AziB。AziB 1催化游离萘甲酸5-甲基-NPA在C3位的区域特异性羟基化反应，生成3-羟基-5-甲基-NPA，所得羟基随后被AziB 2 O-甲基化，得到甲氧基官能团。双结构域NRPS AziA 1通过不寻常的A结构域特异性地掺入3-甲氧基-5-甲基-NPA，以启动azinomycin B的骨架形成。AziA 1激活天然起始单元的几种类似物，表明通过代谢工程生产新的azinomycin类似物的潜力，这些类似物在其NPA部分中不同。
Azinomycin B is a potent antitumor antibiotic that features a set of unusual, densely assembled functionalities. Among them, the 3-methoxy-5-methylnaphthoic acid (NPA) moiety provides an important noncovalent association with DNA, and may, therefore, contribute to the specificity of DNA alkylation for biological activity exhibition. We have previously cloned and sequenced the azinomycin B biosynthetic gene cluster, and proposed that four enzymes: AziB, AziB1, AziB2, and AziA1, are involved in the naphthoate moiety formation and incorporation. In this study, we report in vivo and/or in vitro characterizations of the P450 hydroxylase AziB1, the O-methyltransferase AziB2, and the substrate specificity of the non-ribosomal peptide synthetase (NRPS) AziA1, providing insights into the timing of individual steps in the late-stage modification of 5-methyl-NPA synthesized by the iterative type I polyketide synthase AziB. AziB1 catalyzes a regiospecific hydroxylation at the C3 position of the free naphthoic acid 5-methyl-NPA to produce 3-hydroxy-5-methyl-NPA, and the resulting hydroxyl group is subsequently O-methylated by AziB2 to furnish the methoxy functionality. The di-domain NRPS AziA1 specifically incorporates 3-methoxy-5-methyl-NPA via an unusual A domain to initiate the backbone formation of azinomycin B. AziA1 activates several analogues of the natural starter unit, suggesting a potential for production by metabolic engineering of new azinomycin analogues differing in their NPA moieties.