Björnberg O, Nyman P O
Department of Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, Sweden.
J Gen Virol. 1996 Dec;77 ( Pt 12):3107-11. doi: 10.1099/0022-1317-77-12-3107.
The enzyme dUTPase catalyses the hydrolysis of dUTP to dUMP and pyrophosphate, thereby suppressing incorporation of uracil into DNA and providing a pool of dUMP, the precursor of dTTP. Hydrolysis of other nucleotides similar in structure to dUTP would conceivably be physiologically detrimental and high specificity of the reaction seems to be necessary. In this work, we characterize the substrate specificity of the dUTPases from herpes simplex virus type 1 (HSV-1) and mouse mammary tumour virus (MMTV) in comparison to the Escherichia coli enzyme. We tested dCTP, dTTP, UTP and dUDP as substrates. Significantly higher reactivity was observed for the HSV-1 enzyme with dCTP and dTTP and for the MMTV enzyme with dTTP and UTP. The lower substrate specificity of the two virus enzymes compared with the bacterial enzyme is discussed in relation to the DNA precursor metabolism during virus replication.
脱氧尿苷三磷酸酶（dUTPase）催化dUTP水解生成dUMP和焦磷酸，从而抑制尿嘧啶掺入DNA，并提供dTTP的前体dUMP库。可以想象，水解与dUTP结构相似的其他核苷酸在生理上是有害的，因此该反应似乎需要高度特异性。在这项研究中，我们将1型单纯疱疹病毒（HSV-1）和小鼠乳腺肿瘤病毒（MMTV）的dUTPase与大肠杆菌的dUTPase进行比较，以表征它们的底物特异性。我们测试了dCTP、dTTP、UTP和dUDP作为底物。结果观察到，HSV-1酶对dCTP和dTTP的反应性显著更高，而MMTV酶对dTTP和UTP的反应性显著更高。文中讨论了与细菌酶相比，这两种病毒酶较低的底物特异性与病毒复制过程中DNA前体代谢的关系。
