Critical contacts between the eukaryotic initiation factor 2B (eIF2B) catalytic domain and both eIF2beta and -2gamma mediate guanine nucleotide exchange.

Diverse guanine nucleotide exchange factors (GEFs) regulate the activity of GTP binding proteins. One of the most complicated pairs is eukaryotic initiation factor 2B (eIF2B) and eIF2, which function during protein synthesis initiation in eukaryotes. We have mutated conserved surface residues within the eIF2B GEF domain, located at the eIF2Bepsilon C terminus.

Crystal structure of the C-terminal WD40 repeat domain of the human Groucho/TLE1 transcriptional corepressor.

Groucho (Gro)/TLE proteins are transcriptional corepressors that lack inherent DNA binding but interact with DNA-bound transcription factors and histones, and recruit histone deacetylases. Groucho-mediated repression is essential in embryonic development and involved in regulation of Wnt signaling in adult tissue. We have determined the 1.