Maltman K L, Neuhard J, Warren R A
Biochemistry. 1981 Jun 9;20(12):3586-91. doi: 10.1021/bi00515a043.
In a nonpermissive host, an amber mutant, am 37, of bacteriophage phi W-14 synthesizes deoxyribonucleic acid (DNA) of considerably greater buoyant density than the DNA synthesized by wild-type phage. The am 37 DNA lacks the hypermodified pyrimidine, alpha-putrescinylthymine (putThy). Instead, it contains a new modified base, 5-[(hydroxymethyl)-O-pyrophosphoryl]uracil (hmPPUra). Extracts of cells infected with wild-type phi W-14 convert the hmPPUra in am 37 DNA to putThy when incubated with putrescine.
在一个非允许宿主中，噬菌体φW - 14的琥珀突变体am 37合成的脱氧核糖核酸（DNA）的浮力密度比野生型噬菌体合成的DNA大得多。am 37 DNA缺乏超修饰嘧啶α-腐胺基胸腺嘧啶（putThy）。相反，它含有一种新的修饰碱基5 - [（羟甲基）-O - 焦磷酸基]尿嘧啶（hmPPUra）。用野生型φW - 14感染的细胞提取物在与腐胺一起孵育时，会将am 37 DNA中的hmPPUra转化为putThy。
