Ubiquitous proteins that transport aminoacyl tRNAs to the ribosomes and participate in their selection by the ribosomes. Translation elongation factors are symbolized Ef-Tu in prokaryotes and Ef-1 in eukaryotes. Comparisons of the amino acid sequences in specific segments of Efs from a variety of prokaryotes and eukaryotes have shown that these molecules are the slowest evolving proteins discovered so far. Therefore, certain sequences from Efs have been used to construct phylogenetic trees to determine critical steps in the early evolution of life. See endokaryotic hypothesis, opisthokonta.
Subjects: Genetics and Genomics.