Mangotoxin:: a novel antimetabolite toxin produced by Pseudomonas syringae inhibiting ornithine/arginine biosynthesis
Mangotoxin:: a novel antimetabolite toxin produced by Pseudomonas syringae inhibiting ornithine/arginine biosynthesis
复制标题
DOI：
10.1016/j.pmpp.2003.11.003
复制
发表时间：
2003-09-01
影响因子：
2.7
通讯作者：
de Vicente, A
中科院分区：
文献类型：
--
作者：
Arrebola, E;Cazorla, FM;de Vicente, A
葡萄假单胞菌芒果根瘤菌是一种常见的寄生植物，也是芒果细菌性根尖坏死的病原。在这项工作中，我们描述了一种新的抗代谢毒素，命名为芒果毒素，生产和初步表征的P.主要从芒果树上分离到的菌株。通过大肠杆菌生长抑制试验检测到毒素，因为生长抑制被L-鸟氨酸逆转而不被N-乙酰基鸟氨酸逆转，这表明芒果毒素可以干扰鸟氨酸/精氨酸生物合成的这一步骤。来自不同芒果毒素产生菌株的无细胞培养物显著降低了来自番茄叶蛋白提取物的鸟氨酸N-乙酰转移酶（OAT; EC 2.3.1.35）的活性，约75%，证实了这种酶是新毒素的靶标。生物化学数据表明，芒果毒素是一种无复杂二级结构（对蛋白酶敏感，但在高温和极端pH下稳定）的寡聚肽（< 3 kDa），与其他抗代谢毒素（如菜豆毒素或tabtoxin）一样。无细胞培养物的HPLC分析使我们能够将芒果毒素活性与从芒果毒素生产菌株中获得的单峰相关联，但不存在于从毒性活性缺陷的衍生突变体中获得的芒果毒素活性。(C)2003爱思唯尔有限公司。保留所有权利。
Pseudomonas syringae pv.. syringae is a common inhabitant of a large variety of plants and the Causal agent of bacterial apical necrosis of mango. In this work, we describe production and preliminary characterization of a novel anti metabolite toxin, designated mangotoxin, by P. syringae pv. syringae strains mainly isolated from mango trees. The toxin was detected by the Escherichia coli growth inhibition assay, since growth inhibition was reversed by L-ornithine and not by N-acetyl ornithine, Suggesting that mangotoxin could interfere with this step of ornithine/arginine biosynthesis. Cell-free culture filtrates from different mangotoxin-producing strains strongly decreased, around 75%, the activity of ornithine N-acetyltransferase (OAT; EC 2.3.1.35) from tomato leaf protein extracts, confirming this enzyme as a target of the novel toxin. Biochemical data suggest that mangotoxin is a hydrophylic oligopeptide (< 3 kDa) without a complex secondary structure (sensitive to proteases, but stable at high temperatures and extreme pH), as other anti metabolite toxins, such as phaseolotoxin or tabtoxin. HPLC analyses of cell-free culture filtrates allowed us to associate mangotoxin activity to a single peak obtained from a mangotoxin-producer strain but not present in filtrates from a derivative mutant defective in the toxic activity. (C) 2003 Elsevier Ltd. All rights reserved.