Characterisation of the mgo operon in Pseudomonas syringae pv. syringae UMAF0158 that is required for mangotoxin production.
Characterisation of the mgo operon in Pseudomonas syringae pv. syringae UMAF0158 that is required for mangotoxin production.
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DOI：
10.1186/1471-2180-12-10
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发表时间：
2012-01-17
期刊：
影响因子：
4.2
通讯作者：
de Vicente A
中科院分区：
文献类型：
--
作者：
Arrebola E;Carrión VJ;Cazorla FM;Pérez-García A;Murillo J;de Vicente A
山竹毒素是由紫丁香假单胞菌产生的一种抗代谢毒素。产生芒果毒素的菌株主要是从有细菌性顶端坏死症状的芒果组织中分离出来的。这种毒素是一种寡肽，可以抑制鸟氨酸N-乙酰转移酶(OAT)，OAT是必需氨基酸鸟氨酸和精氨酸生物合成途径中的关键酶。一个推测的非核糖体多肽合成酶基因(MgoA)参与了芒果毒素的产生和毒力。在本研究中，我们进行了RT-PCR分析、插入失活突变、启动子表达分析和终止子定位，以研究含有mgoA基因的基因簇。此外，我们还评估了mgoC、mgoA和mgoD在芒果毒素生产中的重要性。序列分析揭示了一种类似操纵子的结构。MgoB基因上游有一个启动子序列，可驱动LacZ转录。MgoD基因下游有两个终止子。RT-PCR实验表明，这四个基因(MgoBCAD)构成了一个转录单位。该操纵子在遗传组织上类似于其他三个已有完整基因组的丁香疫霉病原变种(紫丁香P.syringae PV.紫丁香B728a、丁香P.syringae p.番茄DC3000和紫丁香P.syringae PV.菜豆1448A)。有趣的是，这三个参考菌株都不能产生芒果毒素。此外，当缺陷突变体与野生型提取物互补时，提取物补充导致芒果毒素生产的恢复。本研究结果证实了mgoB、mgoC、mgoA和mgoD作为转录单位和操纵子的功能。虽然这个操纵子由四个基因组成，但只有最后三个基因直接参与了芒果毒素的生产。
Mangotoxin is an antimetabolite toxin that is produced by strains of Pseudomonas syringae pv. syringae; mangotoxin-producing strains are primarily isolated from mango tissues with symptoms of bacterial apical necrosis. The toxin is an oligopeptide that inhibits ornithine N-acetyl transferase (OAT), a key enzyme in the biosynthetic pathway of the essential amino acids ornithine and arginine. The involvement of a putative nonribosomal peptide synthetase gene (mgoA) in mangotoxin production and virulence has been reported. In the present study, we performed a RT-PCR analysis, insertional inactivation mutagenesis, a promoter expression analysis and terminator localisation to study the gene cluster containing the mgoA gene. Additionally, we evaluated the importance of mgoC, mgoA and mgoD in mangotoxin production. A sequence analysis revealed an operon-like organisation. A promoter sequence was located upstream of the mgoB gene and was found to drive lacZ transcription. Two terminators were located downstream of the mgoD gene. RT-PCR experiments indicated that the four genes (mgoBCAD) constitute a transcriptional unit. This operon is similar in genetic organisation to those in the three other P. syringae pathovars for which complete genomes are available (P. syringae pv. syringae B728a, P. syringae pv. tomato DC3000 and P. syringae pv. phaseolicola 1448A). Interestingly, none of these three reference strains is capable of producing mangotoxin. Additionally, extract complementation resulted in a recovery of mangotoxin production when the defective mutant was complemented with wild-type extracts. The results of this study confirm that mgoB, mgoC, mgoA and mgoD function as a transcriptional unit and operon. While this operon is composed of four genes, only the last three are directly involved in mangotoxin production.
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DOI：
10.1007/978-1-61779-412-4_16
发表时间：
2011-01-01
期刊：
SYNTHETIC GENE NETWORKS: METHODS AND PROTOCOLS
影响因子：
--
作者：
Martinez-Garcia, Esteban;de Lorenzo, Victor
通讯作者：
de Lorenzo, Victor
影响因子：
2.7
作者：
IACOBELLIS, NS;LAVERMICOCCA, P;BALLIO, A
通讯作者：
BALLIO, A
影响因子：
5.4
作者：
Solaiman, Daniel K. Y.;Swingle, Bryan M.
通讯作者：
Swingle, Bryan M.
影响因子：
3.2
作者：
Aguilera, Selene;Lopez-Lopez, Karina;Alvarez-Morales, Ariel
通讯作者：
Alvarez-Morales, Ariel
影响因子：
3.2
作者：
Hillerich, Brandan;Westpheling, Janet
通讯作者：
Westpheling, Janet