Warner H R, Duncan B K
Nature. 1978 Mar 2;272(5648):32-4. doi: 10.1038/272032a0.
T4 bacteriophage DNA containing as much as 30% of its thymine replaced by uracil can be synthesised in Escherichia coli deficient in both dUTPase and uracil--DNA glycosidase. This uracil-containing DNA is competent for RNA transcription, and can be packaged into phage which are viable, if the host cells are deficient in uracil--DNA glycosidase activity. If the host cells are not deficient in this glycosidase activity the infecting phage DNA is rapidly attacked, resulting in more than 50% acid-solubilisation of the DNA. The infected cells are inefficiently killed, presumably because of very limited, if any, expression of the phage DNA. These results indicate that this replacement of thymine by uracil in DNA does not seriously impair the biological functionality of T4 DNA, provided the DNA is not subjected to the breakdown (repair) pathway initiated by uracil--DNA glycosidase.
在缺乏dUTPase和尿嘧啶-DNA糖基化酶的大肠杆菌中，可以合成胸腺嘧啶多达30%被尿嘧啶取代的T4噬菌体DNA。这种含尿嘧啶的DNA能够进行RNA转录，并且如果宿主细胞缺乏尿嘧啶-DNA糖基化酶活性，它可以被包装成活的噬菌体。如果宿主细胞不缺乏这种糖基化酶活性，感染的噬菌体DNA会迅速受到攻击，导致超过50%的DNA酸溶性增加。被感染的细胞被低效杀死，推测是因为噬菌体DNA的表达非常有限（如果有的话）。这些结果表明，只要DNA不受到由尿嘧啶-DNA糖基化酶启动的降解（修复）途径的影响，DNA中胸腺嘧啶被尿嘧啶取代不会严重损害T4 DNA的生物学功能。
