Figure 3.

Binding of various IF-2_mt derivatives to mitochondrial fMet-tRNA. (A) Domain organization of bovine IF-2_mt and the derivatives used to determine the domain(s) of IF-2_mt responsible for the interaction with fMet-tRNA. The domains have been assigned based on the E.coli IF-2 nomenclature (22) and the amino acid residues that encompasses each domain are indicated. (B) The relative percentage of fMet-tRNA protected was calculated based on the amount of [³⁵S]fMet-tRNA (2.5 pmol input, 0.1 μM) protected by 1.0 μM of each derivative. The percentage of fMet-tRNA protected by the full-length IF-2_mt was set at 100% (∼5% of input tRNA) to facilitate comparison. The amount of [³⁵S]fMet-tRNA that remained in the absence of IF-2_mt has been subtracted from each value (0.05 pmol).