Manning P A, Timmis J K, Moll A, Timmis K N
Mol Gen Genet. 1982;187(3):426-31. doi: 10.1007/BF00332623.
The isolation of a series of plasmid mutant derivatives that overproduce the traT outer membrane protein, TraTp, is described. Some of the mutants directed the synthesis of 10-fold more TraTp (200,000 copies/cell) than did the parental plasmid (20,000 copies/cell). The proteins specified by all mutant plasmids except one were correctly inserted into the outer membrane and exposed on the cell surface. The TraTp that was not correctly inserted did not mediate the expected levels of surface exclusion and serum resistance, suggesting that surface localization is a requirement of TraTp function. The overproduction of TraTp was deleterious to bacterial growth, particularly that of minicell mutants of E. coli K-12.
本文描述了一系列过量产生traT外膜蛋白TraTp的质粒突变衍生物的分离情况。一些突变体指导合成的TraTp比亲本质粒（20,000拷贝/细胞）多10倍（200,000拷贝/细胞）。除一个突变体质粒外，所有突变体质粒所指定的蛋白质都正确插入外膜并暴露于细胞表面。未正确插入的TraTp不能介导预期水平的表面排斥和血清抗性，这表明表面定位是TraTp发挥功能的必要条件。TraTp的过量产生对细菌生长有害，尤其是对大肠杆菌K-12的微小细胞突变体。
