Identification of gntK, a gene required for the methylation of purpurosamine C-6′ in gentamicin biosynthesis
Identification of gntK, a gene required for the methylation of purpurosamine C-6′ in gentamicin biosynthesis
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gntK 的鉴定，庆大霉素生物合成中紫胺 C-6â2 甲基化所需的基因
DOI：
10.2323/jgam.58.349
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发表时间：
2012-01-01
影响因子：
1.2
通讯作者：
Yan, Lingbin
中科院分区：
文献类型：
--
作者：
Hong, Wenrong;Yan, Lingbin
庆大霉素和西索米星是两种不同的氨基糖苷类抗生素。化学结构和生物合成基因簇的比较，加上生物信息学分析，表明gntK基因可能与甲基化有关。gntK基因片段在M.利用基因工程技术对紫球藻G1008进行了灭活，并对其突变株M.筛选到了紫花苜蓿GK 1101（Delta gntK）。通过HPLC-MS分析G1008和GK 1101的代谢产物，发现GK 1101不再产生庆大霉素C-1或C-2，而主要合成庆大霉素C-1a，并且C-1a的产量显著增加。这表明庆大霉素C-1和C-2生物合成的代谢流通过破坏gntK基因而被阻断，这证实了gntK基因编码催化红嘌呤胺C-6 '甲基化的酶。突变株GK 1101具有良好的工业应用前景。此外，我们的研究提供了可用于阐明单个基因功能和简化重要药用微生物靶向遗传育种的信息。
Gentamicin and sisomicin are two different aminoglycoside antibiotics. The comparison of their chemical structure and biosynthetic gene clusters, coupled with bioinformatic analysis, suggested that the gntK gene would be associated with methylation. The gntK gene fragment in M. purpurea G1008 was inactivated by genetic engineering and its mutant strain M. purpurea GK1101 (Delta gntK) was screened. The metabolites of G1008 and GK1101 was analyzed by HPLC-MS, which revealed that GK1101 no longer produced gentamicin C-1 or C-2, while mainly synthesizing gentamicin C-1a, and the production of C-1a increased significantly. This indicated that the metabolic flow for the gentamicin C-1 and C-2 biosynthesis was blocked by disrupting the gntK gene, which substantiated that the gntK gene encoded the enzyme that catalyzes the methylation of purpurosamine C-6'. The mutant GK1101 has good prospects for industrial application. In addition, our study provides information that can be used to clarify the function of a single gene and simplify the targeted genetic breeding of important pharmaceutical microorganisms.