Table 1.

Functions of different eIFs.

Protein	Function	Refs.
eIF1	mRNA screening and delivery of tRNA.	[23, 101]
eIF2	Initiation codon recognition.	[27]
eIF2b	Allows for the next initiation to occur (returns the released GDP to GTP).
eIF3	Recruiting translation factors and 40S ribosome subunits to the mRNA.	[23, 24, 102]
eIF4F	Multisubunit complex:	[24, 103]
(i) eIF4E	CAP binding activity, a rate-limiting factor.
(ii) eIF4G	Scaffolding protein and interaction partner for other factors.
(iii) eIF4A	RNA helicase.
(iv) eIF4B and eIF4H	mRNA secondary structure unwinding.
eLF5	Translation elongation and bond formation.	[23]
eIF6	Prevents 60S subunit association with 40S subunit in the absence of mRNA (antiassociation factor).	[25]

eIF: eukaryotic initiation factor; mRNA: messenger RNA; tRNA: tranfer RNA; GDP: glutamine dipeptide; GTP: glutamine tripeptide; CAP: catabolite activator protein.