Component of the protein complex eIF4F, which is involved in the recognition of the mRNA cap, ATP-dependent unwinding of 5'-terminal secondary structure and recruitment of mRNA to the ribosome (By similarity). Recognizes and binds the 7-methylguanosine-containing mRNA cap during an early step in the initiation of protein synthesis and facilitates ribosome binding by inducing the unwinding of the mRNAs secondary structures (By similarity). Key component of recessive resistance to potyviruses (PubMed:17584936). (Microbial infection) Susceptibility host factor required for viral infection by recruiting viral RNAs to the host ribosomal complex via an interaction with viral genome-linked protein (VPg). EIF4F is a multi-subunit complex, the composition of which varies with external and internal environmental conditions. It is composed of at least EIF4A, EIF4E and EIF4G. EIF4E is also known to interact with other partners. In higher plants two isoforms of EIF4F have been identified, named isoform EIF4F and isoform EIF(iso)4F. Isoform EIF4F has subunits p220 and p26, whereas isoform EIF(iso)4F has subunits p82 and p28. (Microbial infection) Interacts with potyvirus viral genome-linked protein (VPg); this interaction is possible in susceptible hosts but impaired in resistant plants. According to the redox status, the Cys-133-Cys-171 disulfide bridge may have a role in regulating protein function by affecting its ability to bind capped mRNA. Displayed sequence is from cv. C-277 and confers resistance to melon necrotic spot virus (MNSV) isolates Malpha5 and 264. Belongs to the eukaryotic initiation factor 4E family.