Structure and Function of Archaeal Translation Initiation Factor 2 Fragments Containing Cys2-Cys2 Motifs.

The heterotrimeric (αβγ) translation initiation factor 2 of archaea and eukaryotes (a/eIF2) supplies the P-site of the ribosome with the initiation tRNA. Its two subunits (β and γ) contain the Cys2-Cys2 motif, which is capable of forming a stable zinc finger structure in the presence of zinc ions. In this work, comparative analysis of the fragments containing Cys2-Cys2 motifs in the aIF2β and aIF2γ structures from different organisms was carried out and their environments in crystals was analyzed. Based on the obtained data, a conclusion was made that the conformation and role of these fragments in the β- and γ-subunits of the aIF2 are different.