Palitti F, Vellante A, Cerio-Ventura G, Fasella P, Salerno C, Whitehead E
Eur J Biochem. 1979 Jun;97(1):147-53. doi: 10.1111/j.1432-1033.1979.tb13096.x.
The ATP-dependent exonuclease V from Micrococcus lysodekticus shows a Michaelian relation between steady-state velocity and the concentration of T7 DNA substrate. The Km (expressed as a mass concentration) does not change when the T7 DNA is broken into smaller fragments by a restriction enzyme. This is interpreted to mean that the predominant process by which the exonuclease-V--DNA complex breaks down is digestion of the entire DNA molecule rather than physical dissociation, in accord with the already known processive nature of degradation by this enzyme. The way that the V and Km towards DNA vary with ATP and ADP concentration suggests that enzyme-DNA complex is predominantly formed by reaction of DNA with an enzyme-ATP complex rather than with bare enzyme.
来自溶壁微球菌的ATP依赖性核酸外切酶V在稳态速度与T7 DNA底物浓度之间呈现米氏关系。当T7 DNA被限制性酶切割成较小片段时，Km（以质量浓度表示）不变。这被解释为意味着核酸外切酶V - DNA复合物分解的主要过程是整个DNA分子的消化而非物理解离，这与该酶已知的持续性降解特性一致。V和Km对DNA的影响方式随ATP和ADP浓度而变化，这表明酶 - DNA复合物主要是由DNA与酶 - ATP复合物反应形成，而非与裸酶反应形成。
