Nagel de Zwaig R, Luria S E
J Bacteriol. 1967 Oct;94(4):1112-23. doi: 10.1128/jb.94.4.1112-1123.1967.
A series of colicin-tolerant (tol) mutants of Escherichia coli K-12, which adsorbed colicins but were not killed by them, were isolated and studied genetically and physiologically. Three major classes of mutants were found: tol II, tolerant to colicins A, E1, E2, E3, and K; tol III, tolerant to A, E2, E3, and K; and tol VIII, tolerant to E1 only. The sites of tol II and tol III mutations mapped near the gal region (gene order: tol-gal-bio) and were cotransduced with gal by P1. In heterozygous diploids, tol(+) was dominant over tol; tol II and tol III gave full complementation. All the tol mutations that mapped near gal rendered the bacteria more fragile during growth and hypersensitive to deoxycholate and to ethylenediaminetetraacetic acid. The tol VIII mutation mapped between str and his. These mutants were extremely sensitive to deoxycholate and were also hypersensitive to methylene blue, acridines, and various other compounds. The sensitivity is attributed to increased uptake due to selective alteration of the permeability barrier. The colicin-tolerant mutations are interpreted as affecting some components of the cytoplasmic membrane which mediate between the adsorbed colicin molecules and the target sites of their biochemical effects in the bacterial cell.
分离出一系列大肠杆菌K - 12的耐大肠杆菌素（tol）突变体，这些突变体能够吸附大肠杆菌素但不会被其杀死，并对其进行了遗传学和生理学研究。发现了三大类突变体：tol II，对大肠杆菌素A、E1、E2、E3和K耐受；tol III，对A、E2、E3和K耐受；以及tol VIII，仅对E1耐受。tol II和tol III突变位点定位于gal区域附近（基因顺序：tol - gal - bio），并被P1噬菌体与gal共转导。在杂合二倍体中，tol(+)对tol呈显性；tol II和tol III表现出完全互补。所有定位于gal附近的tol突变都会使细菌在生长过程中更脆弱，并且对脱氧胆酸盐和乙二胺四乙酸高度敏感。tol VIII突变定位于str和his之间。这些突变体对脱氧胆酸盐极其敏感，并且对亚甲蓝、吖啶和各种其他化合物也高度敏感。这种敏感性归因于由于通透性屏障的选择性改变导致摄取增加。耐大肠杆菌素突变被解释为影响细胞质膜的某些成分，这些成分在吸附的大肠杆菌素分子与其在细菌细胞中的生化作用靶点之间起介导作用。
