cd03181

Glutathione S-transferase C-terminal-like, alpha helical domain of the Gamma subunit of Elongation Factor 1B and similar proteins; Glutathione S-transferase (GST) C-terminal domain family, Gamma subunit of Elongation Factor 1B (EF1Bgamma) subfamily; EF1Bgamma is part of the eukaryotic translation elongation factor-1 (EF1) complex which plays a central role in the elongation cycle during protein biosynthesis. EF1 consists of two functionally distinct units, EF1A and EF1B. EF1A catalyzes the GTP-dependent binding of aminoacyl-tRNA to the ribosomal A site concomitant with the hydrolysis of GTP. The resulting inactive EF1A:GDP complex is recycled to the active GTP form by the guanine-nucleotide exchange factor EF1B, a complex composed of at least two subunits, alpha and gamma. Metazoan EFB1 contain a third subunit, beta. The EF1B gamma subunit contains a GST fold consisting of an N-terminal thioredoxin-fold domain and a C-terminal alpha helical domain. The GST-like domain of EF1Bgamma is believed to mediate the dimerization of the EF1 complex, which in yeast is a dimer of the heterotrimer EF1A:EF1Balpha:EF1Bgamma. In addition to its role in protein biosynthesis, EF1Bgamma may also display other functions. The recombinant rice protein has been shown to possess GSH conjugating activity. The yeast EF1Bgamma binds to membranes in a calcium dependent manner and is also part of a complex that binds to the msrA (methionine sulfoxide reductase) promoter suggesting a function in the regulation of its gene expression. Also included in this subfamily is the GST_C-like domain at the N-terminus of human valyl-tRNA synthetase (ValRS) and its homologs. Metazoan ValRS forms a stable complex with Elongation Factor-1H (EF-1H), and together, they catalyze consecutive steps in protein biosynthesis, tRNA aminoacylation and its transfer to EF.