Fitzgibbon J E, Braymer H D
Department of Microbiology, Louisiana State University, Baton Rouge 70803.
Appl Environ Microbiol. 1990 Nov;56(11):3382-8. doi: 10.1128/aem.56.11.3382-3388.1990.
A plasmid carrying a 2.4-kilobase-pair fragment of DNA from Pseudomonas sp. strain PG2982 has been isolated which was able to increase the glyphosate resistance of Escherichia coli cells. The increase in resistance was dependent on the presence of a plasmid-encoded protein with a molecular weight of approximately 33,000, the product of a translational fusion between a gene on the vector, pACYC184, and the insert DNA. An overlapping region of the PG2982 chromosome carrying the entire gene (designated igrA) was cloned, and a plasmid (pPG18) carrying the gene was also able to increase glyphosate resistance in E. coli. A protein with a molecular weight of approximately 40,000 was encoded by the PG2982 DNA contained in pPG18. This plasmid was not able to complement a mutation in the gene for 5-enolpyruvylshikimate-3-phosphate synthase (aroA) in E. coli, and modification of glyphosate by E. coli cells containing the plasmid could not be demonstrated. The nucleotide sequence of the PG2982 DNA contained an open reading frame able to encode a protein with a calculated molecular weight of 39,396.
已分离出一种携带来自假单胞菌属PG2982菌株的2.4千碱基对DNA片段的质粒，该质粒能够提高大肠杆菌细胞对草甘膦的抗性。抗性的提高取决于一种分子量约为33,000的质粒编码蛋白的存在，该蛋白是载体pACYC184上的一个基因与插入DNA之间翻译融合的产物。克隆了携带整个基因（命名为igrA）的PG2982染色体的重叠区域，携带该基因的质粒（pPG18）也能够提高大肠杆菌对草甘膦的抗性。pPG18中所含的PG2982 DNA编码一种分子量约为40,000的蛋白质。该质粒不能互补大肠杆菌中5-烯醇丙酮酸莽草酸-3-磷酸合酶（aroA）基因的突变，并且无法证明含有该质粒的大肠杆菌细胞对草甘膦的修饰作用。PG2982 DNA的核苷酸序列包含一个开放阅读框，能够编码一种计算分子量为39,396的蛋白质。
