Kolesnikov Alexander, Gudkov Anatoly
Institute of Protein Research, Russian Academy of Sciences, 142290, Moscow Region, Pushchino, Russia.
FEBS Lett. 2002 Mar 6;514(1):67-9. doi: 10.1016/s0014-5793(02)02300-1.
Elongation factors Tu and G (EF-Tu and EF-G) alternately interact with the ribosome during the elongation phase of protein biosynthesis. The function of both factors depends on GTP binding, and the factors are ascribed to a superfamily of G-proteins. All G-proteins contain the effector loop, a structural element that is important for the protein's interaction with its target molecule. In this study the effector loop of EF-G was replaced by the loop taken from EF-Tu. The EF-G with EF-Tu loop has markedly decreased GTPase activity and did not catalyze translocation. We conclude that these loops are not functionally interchangeable since the factors interact with different states of the ribosome.
延伸因子Tu和G（EF-Tu和EF-G）在蛋白质生物合成的延伸阶段交替与核糖体相互作用。这两种因子的功能都依赖于GTP结合，并且这些因子属于G蛋白超家族。所有G蛋白都含有效应环，这是一种对蛋白质与其靶分子相互作用很重要的结构元件。在本研究中，EF-G的效应环被取自EF-Tu的环所取代。带有EF-Tu环的EF-G的GTP酶活性显著降低，并且不催化转位。我们得出结论，这些环在功能上不可互换，因为这些因子与核糖体的不同状态相互作用。
