Beaudry P, Begard E, Douzou P, Grunberg-Manago M
Eur J Biochem. 1978 Dec;92(2):613-9. doi: 10.1111/j.1432-1033.1978.tb12784.x.
fMet-tRNAfMet binding to both 30-S subunits and to 70-S particles is dependent on both pH AND Mg2+ concentration: for fMet-tRNAfMet binding to 70-S particles, variations of pH and Mg2+ concentration are tightly interdependent. This behavior can be interpreted by the polyelectrolyte theory as a direct consequence of the fact that the binding occurs in a polyanionic micro-environment. The pH-dependent binding to 70-S particles clearly shows the involvement of two prototropic groups which appear to be those carrying out GTP hydrolysis, therefore directly linked to initiation complex formation; in the presence of a non-hydrolyzable analogue to GTP, guanosine 5'-[beta, gamma-imido]triphosphate, the binding of fMet-tRNAfMet shows much less interdependence between variation of pH and Mg2+ concentration.
甲酰甲硫氨酰 - tRNAfMet与30 - S亚基以及70 - S颗粒的结合都依赖于pH值和Mg2 +浓度：对于甲酰甲硫氨酰 - tRNAfMet与70 - S颗粒的结合，pH值和Mg2 +浓度的变化紧密相关。这种行为可以根据聚电解质理论解释为结合发生在聚阴离子微环境这一事实的直接结果。甲酰甲硫氨酰 - tRNAfMet与70 - S颗粒的pH依赖性结合清楚地表明有两个质子转移基团参与其中，这两个基团似乎是进行GTP水解的基团，因此与起始复合物的形成直接相关；在存在GTP的不可水解类似物鸟苷5'-[β,γ-亚氨基]三磷酸的情况下，甲酰甲硫氨酰 - tRNAfMet的结合在pH值和Mg2 +浓度变化之间的相互依赖性要小得多。
