IF4B contains 1 RRM (RNA recognition motif) domain and is required for the binding of mRNA to ribosomes. Functions of EIF4B are in close association with EEF4-F and EIF4-A. It binds near the 5μ-terminal cap of mRNA in presence of EIF-4F and ATP and promotes the ATPase activity and the ATP-dependent RNA unwinding activity of both EIF4-A and EIF4-F.
