Beck B D, Arscott P G, Jacobson A
Proc Natl Acad Sci U S A. 1978 Mar;75(3):1250-4. doi: 10.1073/pnas.75.3.1250.
We have characterized novel properties of the bacterial protein synthesis elongation factor Tu which indicate that it may function as a structural protein. Under appropriate conditions, elongation factor Tu polymerizes to form filaments and, more often, bundles of filaments. It is also the predominant component of a complex of proteins from Escherichia coli that undergoes reversible polymerization in the presence of KCl and MgCl2. In addition, purified elongation factor Tu binds tightly to DNase I in the presence of 10 mM MgCl2. In crude extracts the factor shows no binding in the presence or absence of MgCl2. These properties suggest that elongation factor Tu may have certain actin-like properties and that it has cellular functions other than its role in protein synthesis.
我们已经对细菌蛋白质合成延伸因子Tu的新特性进行了表征，这些特性表明它可能作为一种结构蛋白发挥作用。在适当条件下，延伸因子Tu会聚合形成细丝，更常见的是形成细丝束。它也是来自大肠杆菌的一组蛋白质复合物的主要成分，该复合物在氯化钾和氯化镁存在的情况下会发生可逆聚合。此外，在10 mM氯化镁存在的情况下，纯化的延伸因子Tu会与脱氧核糖核酸酶I紧密结合。在粗提物中，无论有无氯化镁，该因子均无结合现象。这些特性表明，延伸因子Tu可能具有某些肌动蛋白样特性，并且它在细胞中除了在蛋白质合成中发挥作用外，还具有其他功能。
