Cross-reactivity studies on the interaction between elongation factors Tu and Ts from Streptomyces aureofaciens and Escherichia coli in the GDP exchange reaction

The method of purification of elongation factor Ts from Streptomyces aureofaciens is described. Purified elongation factors Ts from S. aureofaciens and Escherichia coli were tested in cross-reactivity studies with elongation factors Tu from both species in a GDP exchange reaction under equilibrium and non-equilibrium conditions. Experiments have revealed that slower spontaneous release of GDP from S. aureofaciens EF-Tu is compensated for by higher affinity of homologous EF-Ts towards EF-Tu and thus the initial rates of EF-Ts catalysed GDP exchange can be kept the same in both E. coli and S. aurefaciens in vitro systems.