cd01883

Elongation Factor 1-alpha (EF1-alpha) protein family; EF1 is responsible for the GTP-dependent binding of aminoacyl-tRNAs to the ribosomes. EF1 is composed of four subunits: the alpha chain which binds GTP and aminoacyl-tRNAs, the gamma chain that probably plays a role in anchoring the complex to other cellular components and the beta and delta (or beta') chains. This subfamily is the alpha subunit, and represents the counterpart of bacterial EF-Tu for the archaea (aEF1-alpha) and eukaryotes (eEF1-alpha). eEF1-alpha interacts with the actin of the eukaryotic cytoskeleton and may thereby play a role in cellular transformation and apoptosis. EF-Tu can have no such role in bacteria. In humans, the isoform eEF1A2 is overexpressed in 2/3 of breast cancers and has been identified as a putative oncogene. This subfamily also includes Hbs1, a G protein known to be important for efficient growth and protein synthesis under conditions of limiting translation initiation in yeast, and to associate with Dom34. It has been speculated that yeast Hbs1 and Dom34 proteins may function as part of a complex with a role in gene expression.