Bernstein A, Rolfe B, Onodera K
J Bacteriol. 1972 Oct;112(1):74-83. doi: 10.1128/jb.112.1.74-83.1972.
Colicin-tolerant mutants of Escherichia coli K-12, which map near gal at 17 min (tolA, B mutants), have been isolated and characterized. These mutants exhibited a very broad spectrum of phenotypic changes consistent with the interpretation that they are cell surface mutants. In addition to being colicintolerant and sensitive to deoxycholate and ethylenediaminetetraacetic acid, tolA, B mutants are sensitive to vancomycin, bacitracin, and dodecyl sulfate. The tolA, B mutants from most strains also formed mucoid colonies at 30 C on nutrient agar plates and had a greatly increased plating efficiency for lysisdefective S mutants of bacteriophage lambda. Complementation analysis showed that the four phenotypic groups of tol mutants that map near gal fall into three complementation groups: tolP, tolA, and tolB. Recombination analysis by three-factor crosses established the order of the three groups as tolP-tolA-tolB-gal. Because of the wide variety of phenotypic changes that accompanies mutation to colicin tolerance, revertants were isolated to test whether single or multiple mutations were involved. The reversion analysis, as well as other genetic criteria, confirmed that only single mutations were involved, suggesting that these pleiotropic changes are a consequence of a single change in the E. coli cell surface.
已分离并鉴定出大肠杆菌K - 12的耐大肠杆菌素突变体，这些突变体位于17分钟处靠近半乳糖的位置（tolA、B突变体）。这些突变体表现出非常广泛的表型变化，这与它们是细胞表面突变体的解释一致。除了不耐大肠杆菌素且对脱氧胆酸盐和乙二胺四乙酸敏感外，tolA、B突变体还对万古霉素、杆菌肽和十二烷基硫酸盐敏感。大多数菌株的tolA、B突变体在30℃的营养琼脂平板上也形成黏液状菌落，并且对噬菌体λ的裂解缺陷型S突变体的平板接种效率大大提高。互补分析表明，位于半乳糖附近的tol突变体的四个表型组可分为三个互补组：tolP、tolA和tolB。通过三因子杂交进行的重组分析确定了这三个组的顺序为tolP - tolA - tolB - 半乳糖。由于伴随耐大肠杆菌素突变出现了各种各样的表型变化，因此分离出回复突变体以测试涉及的是单个还是多个突变。回复突变分析以及其他遗传标准证实只涉及单个突变，这表明这些多效性变化是大肠杆菌细胞表面单一变化的结果。
