Dinçbaş V, Bilgin N, Scoble J, Ehrenberg M
Department of Molecular Biology, BMC, Uppsala, Sweden.
FEBS Lett. 1995 Jan 2;357(1):19-22. doi: 10.1016/0014-5793(94)01318-u.
Recent observations indicate that the stoichiometry for the complex between EF-Tu.GTP and aminoacyl-tRNA (aa-tRNA) changes with temperature. At 37 degrees C two EF-Tu.GTPs bind one aa-tRNA in an extended ternary complex, but at 0 degrees C the complex has 1:1 stoichiometry. However, the present experiments show that there are two GTPs hydrolyzed on EF-Tu per peptide bond in poly(Phe) synthesis at 37 degrees C as well as at 0 degrees C. This indicates two different pathways for the enzymatic binding of aa-tRNA to the A-site on the ribosome.
最近的观察结果表明，EF-Tu·GTP与氨酰-tRNA（aa-tRNA）之间复合物的化学计量比随温度变化。在37℃时，两个EF-Tu·GTP在一个延伸的三元复合物中结合一个aa-tRNA，但在0℃时，该复合物的化学计量比为1:1。然而，目前的实验表明，在37℃以及0℃下合成聚（苯丙氨酸）时，每个肽键在EF-Tu上有两个GTP被水解。这表明aa-tRNA与核糖体A位点的酶促结合存在两条不同的途径。
