Albright L M, Geiduschek E P
J Virol. 1983 Jul;47(1):77-88. doi: 10.1128/JVI.47.1.77-88.1983.
A plasmid containing a copy of the late gene 23 was cleaved at two specific locations after bacteriophage T4 infection. Cleavage at the major site, which is at the 3' end of gene 23, was detected only in the absence of gene 46 product function and was independent of the state of modification of cytosine residues. Cutting of plasmid (cytosine-containing) DNA at this site was independent of phage DNA replication and late transcription functions. A second cleavage site, in vector DNA, was also mapped. The minor extent of cutting at this site was independent of gene 46 function. Gene 46 codes for, or controls, an exonuclease involved in T4 DNA recombination and in degradation of cytosine-containing DNA.
携带晚期基因23拷贝的质粒在噬菌体T4感染后于两个特定位置被切割。主要切割位点位于基因23的3'端，仅在缺乏基因46产物功能时被检测到，且与胞嘧啶残基的修饰状态无关。该位点处质粒（含胞嘧啶）DNA的切割与噬菌体DNA复制和晚期转录功能无关。还确定了载体DNA中的第二个切割位点。该位点较小程度的切割与基因46功能无关。基因46编码或控制一种参与T4 DNA重组和含胞嘧啶DNA降解的核酸外切酶。
