Wheat germ S100 supernatant was resolved into 10 components, all of which are required for tobacco mosaic virus RNA-directed incorporation of amino acid into protein. Two of the components, C2b and C2a, are, respectively, elongation factors 1 and 2, having molecular weights of 51,000 and 72,000. A third factor (C2e) binds Met-tRNA in a GTP-requiring reaction and is absolutely required for the formation of both 40 S ribosome.Met-tRNAiMet and 80 S ribosome.Met-tRNAiMet complexes. This factor is considered to be eucaryotic initiation factor 2. Formation of 80 S ribosome Met-tRNAiMet complexes is augmented 2 to 3-fold by the simultaneous addition of an mRNA, factor C1, and fraction D2(a + b). Factor C1 also reverses the inhibition of translation by an increased concentration of monovalent cations and promotes the translation of a "competitively inhibited" mRNA. These observations suggest that factor C1 and either factor D2a and D2b (or both) function in mRNA attachment reactions. Factor C1 has a molecular weight of 115,000 and appears to be made up of two or three subunits. Factor D2b has been purified to essential homogeneity and has a molecular weight of 55,000. Its interaction with mRNA and its molecular weight suggest that this factor is the wheat germ equivalent of reticulocyte eucaryotic initiation factor 4A.