Krüger D H, Hansen S, Schroeder C
Z Allg Mikrobiol. 1980;20(8):495-502.
Bacterial virus T3 undergoes host-controlled modification which is not based on "classical" processes of DNA modification and restriction. The adsorption and thus the growth of T3 on Escherichia coli W cells (E. coli K12 derivative) decisively depends on the host strain on which the virus was previously propagated. Depending on the modification conferred to the virus by its last host, its efficiency of plating (e.o.p.) on E. coli W varies by six orders of magnitude between 10(-7) and 10(-1). This does not reflect the appearance of T3 host-range mutants, but a fully reversible modification of genotypically unchanged T3 wild-type phage. The behaviour of T3 in the described host system constitutes a second case of so-called non-classical modification and restriction (KRUGER et al. 1977, Molec. gen. Genet. 153, 107-110) of bacteriophages. Non-classical modification (protein modification) is additive to and independent of DNA modification and restriction as demonstrated with the ocr- phage T3/R7. - Furthermore, our results suggest that the adsorption specificity of T3 is determined by at least two independent genetic factors; in both of these factors T3 differs from T7.
细菌病毒T3会经历宿主控制的修饰，这种修饰并非基于DNA修饰和限制的“经典”过程。T3在大肠杆菌W细胞（大肠杆菌K12衍生物）上的吸附以及生长，决定性地取决于病毒先前繁殖所依赖的宿主菌株。根据其最后一个宿主赋予病毒的修饰，T3在大肠杆菌W上的平板效率（e.o.p.）在10^(-7)至10^(-1)之间变化六个数量级。这并非反映T3宿主范围突变体的出现，而是基因型未改变的T3野生型噬菌体的完全可逆修饰。T3在所描述的宿主系统中的行为构成了噬菌体所谓非经典修饰和限制（KRUGER等人，1977年，分子遗传学杂志153卷，107 - 110页）的第二个案例。非经典修饰（蛋白质修饰）与DNA修饰和限制相加且独立，正如ocr - 噬菌体T3/R7所证明的那样。此外，我们的结果表明，T3的吸附特异性由至少两个独立的遗传因素决定；在这两个因素中，T3都与T7不同。
