[Encoded by human EEF2 Gene (EF-G/EF-2 Family), highly conserved 857-aa 95-kDa cytoplasmic Elongation Factor 2 is essential for protein synthesis and required for GTP-dependent ribosomal A-site to P-site translocation of nascent protein chains: peptidyl-tRNA is moved from the ribosome acceptor site to the next mRNA codon by hydrolysis of GTP bound to EF2. EF2 is completely inactivated by EF-2 kinase phosphorylation. Diphtheria and PA toxins inhibit protein synthesis by catalyzing covalent ADP-ribosylation of EF2 (from NAD). (NCI) ( NCI )]