Trichothecene 3-O-acetyltransferase protects both the producing organism and transformed yeast from related mycotoxins -: Cloning and characterization of Tri101
Trichothecene 3-O-acetyltransferase protects both the producing organism and transformed yeast from related mycotoxins -: Cloning and characterization of Tri101
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DOI：
10.1074/jbc.273.3.1654
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发表时间：
1998-01-16
影响因子：
4.8
通讯作者：
Yamaguchi, I
中科院分区：
文献类型：
--
作者：
Kimura, M;Kaneko, I;Yamaguchi, I
脱氧雪腐镰刀菌烯醇、4，15-二乙酰氧基环烯醇和T-2毒素等三氯乙烯类真菌毒素是真核生物蛋白质合成的有效抑制因子。用兔网织红细胞翻译系统对这些毒素的3-O-乙酰基的体外活性进行了测定。结果表明，在生物合成途径的C-3位引入O-乙酰基是产生t型毛霉烯的镰刀菌的抗性机制。已从设计用于在裂殖酵母中表达的禾谷镰刀菌cDNA文库中成功克隆。裂解酵母转化子的选择是因为它们在T-2毒素存在下生长的能力，这一策略允许分离到25个抗性克隆，所有克隆都包含一个来自抗生素产生菌的药物失活O-乙酰基转移酶基因Tri101，这是第一个来自抗生素产生菌的药物失活O-乙酰基转移酶基因，Tri101编码一个451个氨基酸残基的多肽，它与迄今报道的任何蛋白质都没有相似之处。重组大肠杆菌的TRI101以乙酰辅酶A依赖的方式催化C-3位毛环的O-乙酰化。以Tri101为探针，从基因组中分离出两个重叠最少的粘粒克隆，覆盖70kb碱基对。禾本科植物。其他三茂铁生物合成基因Tri4、Tri5和Tri6没有聚集在这些粘粒克隆覆盖的区域，这些新的粘粒克隆被认为位于大的生物合成基因簇的其他部分，可能对三茂铁生物合成的研究有用。
Trichothecene mycotoxins such as deoxynivalenol, 4,15-diacetoxyscirpenol, and T-2 toxin, are potent protein synthesis inhibitors for eukaryotic organisms, The 3-O-acetyl derivatives of these toxins were shown to reduce their in vitro activity significantly as assessed by assays using a rabbit reticulocyte translation system, The results suggested that the introduction of an O-acetyl group at the C-3 position in the biosynthetic pathway works as a resistance mechanism for Fusarium species that produce t-type trichothecenes (trichothecenes synthesized via the precursor trichotriol).A gene responsible for the 3-O-acetylation reaction, Tri101, has been successfully cloned from a Fusarium graminearum cDNA library that was designed to be expressed in Schizosaccharomyces pombe. Fission yeast transformants were selected for their ability to grow in the presence of T-2 toxin, and this strategy allowed isolation of 25 resistant clones, all of which contained a cDNA for Tri101, This is the first drug-inactivating O-acetyltransferase gene derived from antibiotic-producing organisms, The open reading frame of Tri101 codes for a polypeptide of 451 amino acid residues, which shows no similarity to any other proteins reported so far, TRI101 from recombinant Escherichia coli catalyzes O-acetylation of the trichothecene ring specifically at the C-3 position in an acetyl-CoA-dependent manner. By using the Tri101 cDNA as a probe, two least overlapping cosmid clones that cover a region of 70 kilobase pairs have been isolated from the genome off. graminearum. Other trichothecene biosynthetic genes, Tri4, Tri5, and Tri6, were not clustered in the region covered by these cosmid clones, These new cosmid clones are considered to be located in other parts of the large biosynthetic gene cluster and might be useful for the study of tricho thecene biosynthesis.