Elongation factor G C-terminus. This domain includes the carboxyl terminal regions of elongation factors (EFs) bacterial EF-G, eukaryotic and archeal EF-2 and eukaryotic mitochondrial mtEFG1s and mtEFG2s. This group also includes proteins similar to the ribosomal protection proteins Tet(M) and Tet(O), BipA, LepA and, spliceosomal proteins: human 116kD U5 small nuclear ribonucleoprotein (snRNP) protein (U5-116 kD) and yeast counterpart Snu114p. This domain adopts a ferredoxin-like fold consisting of an alpha-beta sandwich with anti-parallel beta-sheets, resembling the topology of domain III found in the elongation factors EF-G and eukaryotic EF-2, with which it forms the C-terminal block. The two domains however are not superimposable and domain III lacks some of the characteristics of this domain. EF-2/EF-G in complex with GTP, promotes the translocation step of translation. During translocation the peptidyl-tRNA is moved from the A site to the P site, the uncharged tRNA from the P site to the E-site and, the mRNA is shifted one codon relative to the ribosome. Tet(M) and Tet(O) mediate Tc resistance. Typical Tcs bind to the ribosome and inhibit the elongation phase of protein synthesis, by inhibiting the occupation of site A by aminoacyl-tRNA. Tet(M) and Tet(O) catalyze the release of tetracycline (Tc) from the ribosome in a GTP-dependent manner. BipA is a highly conserved protein with global regulatory properties in Escherichia coli. Yeast Snu114p is essential for cell viability and for splicing in vivo. Experiments suggest that GTP binding and probably GTP hydrolysis is important for the function of the U5-116 kD/Snu114p. The function of LepA proteins is unknown.
Jiyao W et al.(2023). "The conserved domain database in 2023.",