“…The formation of a ternary complex starting with 30S, poly(U), and A-AcPhe-tRNA can be regarded as analogous to an enzymatic reaction involving one enzyme (30 S) and two substrates (poly(U) and TV-AcPhe-tRNA). In these reactions different pathways can lead to the formation of the ternary complex and the rate equations for the various mechanisms have been derived (Laedler and Socquet, 1950;Segal et al, 1952;Ingraham and Makower, 1954;Alberty, 1956;Fromm, 1975). In the case of the 30S initiation complex two different pathways have been proposed (Noll and Noll, 1974; Jay and Kaempfer, 1975;Benne et al, 1973;Vermeer et al, 1973).…”