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 prokaryot ic cells. Its general function in protein biosynthesis is well establi shed. It is a member of the large family of G-proteins, all of which b ind guanosine phosphates (GDP or GTP) as cofactors. In its active GTP bound state EF-Tu binds aminoacylated tRNA (aa-tRNA) forming the terna ry complex EF-Tu:GTP:aa-tRNA. The ternary complex interacts with the r ibosome where the anticodon on tRNA recognises a codon on mRNA, GTPase activity is induced and inactive EF-Tu:GDP is released. Here we repor t the successful crystallization of a ternary complex of Thermus aquat icus EF-Tu:GDPNP and yeast Phe-tRNA(Phe) after its purification by HPL C.