Gumport R I, Lehman I R
Proc Natl Acad Sci U S A. 1971 Oct;68(10):2559-63. doi: 10.1073/pnas.68.10.2559.
Proteolytic degradation of the Escherichia coli DNA ligase-adenylate intermediate releases adenosine 5'-monophosphate linked to the epsilon-amino group of lysine by a phosphoamide bond. Measurements of the rate of hydroxylaminolysis of the ligase-adenylate provide further support for a phosphoamide linkage in the native enzyme. Lysine (epsilon-amino)-linked adenosine monophosphoramidate has also been isolated from the T4 phage-induced ligase-adenylate intermediate. These results indicate that an initial step of the DNA ligase reaction consists of the nucleophilic attack of the epsilon-amino group of a lysine residue of the enzyme on the adenylyl phosphorus of DPN or ATP that leads to the formation of enzyme-bound lysine (epsilonamino)-linked adenosine monophosphoramidate.
大肠杆菌DNA连接酶-腺苷酸中间体的蛋白水解降解会释放出通过磷酰胺键与赖氨酸的ε-氨基相连的5'-单磷酸腺苷。对连接酶-腺苷酸的羟氨解速率的测量进一步支持了天然酶中存在磷酰胺键。赖氨酸（ε-氨基）连接的单磷酸腺苷酰胺也已从T4噬菌体诱导的连接酶-腺苷酸中间体中分离出来。这些结果表明，DNA连接酶反应的初始步骤包括酶的赖氨酸残基的ε-氨基对DPN或ATP的腺苷酰磷进行亲核攻击，从而导致形成酶结合的赖氨酸（ε-氨基）连接的单磷酸腺苷酰胺。
