Havekes L, Tommassen J, Hoekstra W, Lugtenberg B
J Bacteriol. 1977 Jan;129(1):1-8. doi: 10.1128/jb.129.1.1-8.1977.
Escherichia coli K-12 F- mutants defective in conjugation with an I-type donor (ConI-) were isolated and characterized. These mutants are specific in that they are conjugation proficient with other types of donor strains. They have an altered susceptibility to phages and detergents. Chemical analysis of the cell envelopes of mutant strains has shown that the lipopolysaccharide (LPS) is altered and that one major outer-membrane protein is absent. Conjugation experiments in which LPS from wild-type cells was added to a mating mixture, made up with wild-type donor and recipient cells, showed inhibition in transconjugant formation when an I-type donor, but not an F-type donor, was used. This strongly suggests that LPS of the recipient cell is directly involved in the ability to mate with an I-type donor but not with an F-type donor. The mutations are located in the 78- to 82-min region of the E. coli map, with one exception where the mutation maps near or in the galactose operon.
分离并鉴定了大肠杆菌K-12 F-突变体，这些突变体在与I型供体（ConI-）的接合过程中存在缺陷。这些突变体具有特异性，因为它们与其他类型的供体菌株接合能力良好。它们对噬菌体和去污剂的敏感性发生了改变。对突变菌株细胞膜的化学分析表明，脂多糖（LPS）发生了变化，并且一种主要的外膜蛋白缺失。在由野生型供体和受体细胞组成的交配混合物中添加野生型细胞的LPS进行接合实验，结果表明，当使用I型供体而非F型供体时，转接合子的形成受到抑制。这有力地表明，受体细胞的LPS直接参与了与I型供体而非F型供体交配的能力。这些突变位于大肠杆菌染色体图谱的78至82分钟区域，只有一个例外，该突变位于半乳糖操纵子附近或其中。
