<p>This entry represents the W2 domain (two invariant tryptophans) and is a region of ~165 amino acids which is found in the C terminus of the following eIFs [<cite idref="PUB00005748"/>, <cite idref="PUB00022408"/>, <cite idref="PUB00040819"/>, <cite idref="PUB00041778"/>]:<p> <ul><li>Eukaryotic translation initiation factor 2B epsilon (eIF-2B-epsilon)</li><li>Eukaryotic translation initiation factor 4 gamma (eIF-4-gamma)</li><li>Eukaryotic translation initiation factor 5 (eIF-5), a GTPase-activating protein (GAP) specific for eIF2</li></ul> </p></p><p>Translation initiation is a sophisticated, well regulated and highly coordinated cellular process in eukaryotes, in which at least 11 eukayrotic initiation factors (eIFs) are included [<cite idref="PUB00005748"/>].</p><p>The W2 domain has a globular fold and is exclusively composed out of alpha-helices [<cite idref="PUB00022408"/>, <cite idref="PUB00040819"/>, <cite idref="PUB00041778"/>]. 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. For example, the W2 domain of H. sapiens eIF5 binds eIF2-beta, eIF3 and eIF1 [<cite idref="PUB00041778"/>], and therefore plays an important role in multifactor complex assembly.</p><p>The entry covers the entire W2 domain.</p>