Gray G L, Vasil M L
J Bacteriol. 1981 Aug;147(2):275-81. doi: 10.1128/jb.147.2.275-281.1981.
Two independently derived, exotoxin A-deficient (Tox- phenotype), nitroso-guanidine-induced mutants of Pseudomonas aeruginosa PAO1 were isolated by using sensitive immunological assays. One mutant, designated PAOT10, was detected as a colony which failed to produce a halo of immunoprecipitation in an antiserum-agar assay. The other mutant (PAOT20) was independently isolated and was detected by a negative reaction in a staphylococcal coagglutination assay with protein A-containing staphylococci and affinity-purified antibodies. Both mutants produced parental levels of extracellular protein. However, whereas the qualitative and quantitative compositions of proteins produced by PAOT20 were indistinguishable from those of the parental strain as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and measurement of extracellular protease, there were marked differences between PAOT10 and the parental strain. The mutation in PAOT10 (tox-1) as mapped by linkage analysis was located between trp-6 and proA. In contrast, linkage analysis and cotransduction placed the mutation in PAOT20 (tox-2), very near trp-6. Data are presented which suggest that tox-1 and tox-2 are regulatory loci.
通过使用灵敏的免疫测定法，分离出了铜绿假单胞菌PAO1的两个独立衍生的、缺乏外毒素A（Tox-表型）的亚硝基胍诱导突变体。一个突变体命名为PAOT10，在抗血清-琼脂试验中被检测为一个菌落，该菌落未能产生免疫沉淀晕圈。另一个突变体（PAOT20）是独立分离得到的，在含有蛋白A的葡萄球菌和亲和纯化抗体的葡萄球菌协同凝集试验中通过阴性反应被检测到。两个突变体产生的细胞外蛋白水平与亲本相同。然而，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和细胞外蛋白酶测定，PAOT20产生的蛋白质的定性和定量组成与亲本菌株没有区别，但PAOT10与亲本菌株之间存在明显差异。通过连锁分析定位的PAOT10中的突变（tox-1）位于trp-6和proA之间。相比之下，连锁分析和共转导将PAOT20中的突变（tox-2）定位在非常靠近trp-6的位置。所提供的数据表明tox-1和tox-2是调控基因座。
