EIF-W2 protein domain
In molecular biology, the protein domain eIF4-gamma/eIF5/eIF2-epsilon is a family of evolutionarily related proteins. This domain is found at the C-terminus of several translation Initiation factors. It was first detected at the very C-termini of the yeast protein GCD6, eIF-2B epsilon, and two other eukaryotic translation initiation factors, eIF-4 gamma and eIF-5 and it may be involved in the interaction of eIF-2B, eIF-4 gamma, and eIF-5 with eIF-2. Function In molecular biology, the eIF-W2 domain functions as the binding site for Mnk eIF4E kinase, an enzyme that phosphorylates eukaryotic initiation factor 4E (eIF4E). For eIF2B-epsilon, the W2 C-terminal domain functions in guanine nucleotide exchange on eIF2. For eIF5, the W2 domain functions in mediating the multifactor complex (MFC) formation with eIF1, eIF2-GTP, eIF3 and Met-tRNAiMet. The eIF5 W2 C-terminal domain and the adjacent N-terminal linker region is responsible for the GDI activity against eIF2-GDP. Domain Structure The W2 domain has a globular fold and is exclusively composed out of alpha-helices. The structure can be divided into a structural C-terminal core onto which the two N-terminal helices are attached. The core contains two aromatic/acidic residue-rich regions (AA boxes), which are important for mediating protein-protein interactions. This entry covers the entire W2