EIF5B
Description
The EIF5B (eukaryotic translation initiation factor 5B) is a protein-coding gene located on chromosome 2.
EIF5B is a protein encoded by the EIF5B gene in humans. It is essential for the accurate initiation of translation in eukaryotes, a complex process involving numerous factors, some of which are multi-subunit complexes. Unlike the simpler bacterial initiation process involving only three factors (IF1, IF2, IF3), eukaryotic initiation involves homologs of IF1 and IF2, namely eIF1A and eIF5B, respectively. EIF5B, encoded by the EIF5B gene, interacts with eIF1A, other initiation factors, and GTP on the ribosome. This interaction positions the initiation methionine tRNA at the start codon of the mRNA, ensuring accurate initiation of translation.
EIF5B is involved in the initiation of protein translation. It acts as a ribosome-dependent GTPase, promoting the joining of the 60S ribosomal subunit to the pre-initiation complex. This forms the 80S initiation complex, where the initiator methionine-tRNA is positioned at the start codon. EIF5B works with eIF1A to correctly position the initiator methionine-tRNA, facilitating the 60S ribosomal subunit joining. Following the formation of the 80S initiation complex, EIF5B is released. While its GTPase activity is not crucial for subunit joining, GTP hydrolysis is essential for the ejection of eIF1A and the subsequent release of EIF5B, ultimately producing elongation-competent ribosomes. Unlike its prokaryotic counterpart, EIF5B does not facilitate the recruitment of Met-rRNA to the small ribosomal subunit.
EIF5B is also known as IF2.
