Purification and crystallization of the ternary complex of elongation factor Tu:GTP and Phe-tRNA(Phe).

Elongation factor Tu (EF-Tu) is the most abundant protein in prokaryotic cells. Its general function in protein biosynthesis is well established. It is a member of the large family of G-proteins, all of which bind guanosine phosphates (GDP or GTP) as cofactors. In its active GTP bound state EF-Tu binds aminoacylated tRNA (aa-tRNA) forming the ternary complex EF-Tu:GTP:aa-tRNA. The ternary complex interacts with the ribosome where the anticodon on tRNA recognises a codon on mRNA, GTPase activity is induced and inactive EF-Tu:GDP is released. Here we report the successful crystallization of a ternary complex of Thermus aquaticus EF-Tu:GDPNP and yeast Phe-tRNA(Phe) after its purification by HPLC.