Nishiyama Y, Maeno K, Yoshida S
Virology. 1983 Jan 30;124(2):221-31. doi: 10.1016/0042-6822(83)90339-2.
A DNA polymerase activity induced by human cytomegalovirus (HCMV) was separated from host cell DNA polymerase and purified by phosphocellulose and DNA-cellulose column chromatography. The DNA polymerase activity was strongly inhibited by phosphonoacetic acid, aphidicolin, araATP, and N-ethylmaleimide, but it was resistant to 2',3'-dideoxyTTP. The sensitivity of HCMV-induced DNA polymerase to these reagents resembles that of host cell DNA polymerase alpha. However, HCMV-induced DNA polymerase activity was stimulated several fold by 100 mM ammonium sulfate, by which DNA polymerase alpha activity was strongly inhibited. Furthermore, it was found that a 3'-to-5' exonuclease activity was tightly associated with the HCMV-induced DNA polymerase. The exonuclease was also stimulated by ammonium sulfate, was inhibited by phosphoacetic acid, and it preferred single-stranded DNA as a substrate. The results suggest that the 3'-to-5' exonuclease may play a role in proofreading in the polymerization process as an integral part of the HCMV-induced DNA polymerase.
人巨细胞病毒（HCMV）诱导产生的一种DNA聚合酶活性从宿主细胞DNA聚合酶中分离出来，并通过磷酸纤维素和DNA纤维素柱色谱法进行纯化。该DNA聚合酶活性受到膦甲酸、阿非迪霉素、araATP和N-乙基马来酰亚胺的强烈抑制，但对2'，3'-双脱氧TTP具有抗性。HCMV诱导的DNA聚合酶对这些试剂的敏感性与宿主细胞DNA聚合酶α相似。然而，100 mM硫酸铵可使HCMV诱导的DNA聚合酶活性提高几倍，而DNA聚合酶α活性则受到强烈抑制。此外，发现一种3'至5'外切核酸酶活性与HCMV诱导的DNA聚合酶紧密相关。该外切核酸酶也受到硫酸铵的刺激，受到膦乙酸的抑制，并且它优先选择单链DNA作为底物。结果表明，3'至5'外切核酸酶可能作为HCMV诱导的DNA聚合酶的一个组成部分，在聚合过程中的校对中发挥作用。
