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 (PubMed:18182024). 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 (PubMed:18182024). Key component of recessive resistance to potyviruses (PubMed:15971038, PubMed:12492847, PubMed:15842624, PubMed:18182024, PubMed:16760413, PubMed:21073716). (Microbial infection) Susceptibility host factor required for viral infection (e.g. potato virus Y (PVY) and tobacco etch virus (TEV)) 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 is impaired in resistant plants (PubMed:15842624, PubMed:18182024). Thus the VPg of tobacco etch virus (TEV) strain HAT interacts with susceptible alleles pvr2(+), pvr2(3) and pvr2(9) but not with the resistant allele pvr2(2), the VPg of TEV strain CAA10 interacts with susceptible alleles pvr2(+), pvr2(2), pvr2(3) and pvr2(9), the VPg of potato virus Y (PVY) strain LYE84 interacts with tomato eIF4E1 and eIF4E2 as well as with the Capsicum annuum eIF4E1 susceptible allele pvr2(+) but not with resistant alleles pvr2(1), pvr2(2), pvr2(3), pvr2(4), pvr2(5), pvr2(6), pvr2(7), pvr2(8) and pvr2(9) and the VPg of PVY strain SON41 interacts with C.annuum eIF4E1 susceptible alleles pvr2(+), pvr2(1), pvr2(2), pvr2(3) and pvr2(4) but not with resistant alleles pvr2(5), pvr2(6), pvr2(7), pvr2(8) and pvr2(9) (PubMed:18182024). In addition, the susceptible allele pvr1(+) interacts strongly with TEV strains HAT and NW VPg while resistance alleles (pvr1, pvr1(1), and pvr1(2)) fail to bind TEV VPg (PubMed:15842624). According to the redox status, the Cys-126-Cys-164 disulfide bridge may have a role in regulating protein function by affecting its ability to bind capped mRNA. Variant present in the strains cv. Serrano Vera Cruz, allele pvr2(7), confers an increased resistance to potato virus Y (PVY) strains LYE84 and SON41 but sensitivity to tobacco etch virus (TEV) strains HAT and CAA10. Variant present in the strains cv. PI195301, allele pvr2(8), confers an increased resistance to potato virus Y (PVY) strains LYE84 and SON41 but sensitivity to tobacco etch virus (TEV) strains HAT and CAA10. Variant present in the strains cv. Chile de Arbol, allele pvr2(9), confers an increased resistance to potato virus Y (PVY) strains LYE84 and SON41 but sensitivity to tobacco etch virus (TEV) strains HAT and CAA10. Variant present in the strains cv. Maroc 1 and LP1, allele pvr2(6), confers an increased resistance to potato virus Y (PVY) strains LYE84 and SON41 but sensitivity to tobacco etch virus (TEV) strains HAT and CAA10. Variant present in the strains cv. Florida VR2, cv. Dempsey, cv. CDP06188 and cv. Chay Angolano, alleles pvr1-2 and pvr2(2), confers an increased resistance to potato virus Y (PVY) strain LYE84 and to tobacco etch virus (TEV) strains HAT and NW associated with impaired TEV VPg binding, but sensitivity to PVY strain SON41 and to TEV strains CAA10. Variant present in the strains cv. HD-C69, cv. PI201234 and cv. Perennial, allele pvr2(3), is associated with an increased resistance to potato virus Y (PVY) strain LYE84 but susceptibility to PVY strain SON41 and to tobacco etch virus (TEV) strains HAT and CAA10. Variant present in the strains cv. Yolo Y and cv. CDP06433, alleles pvr1-1 and pvr2(1), is associated with an increased resistance to potato virus Y (PVY) strain LYE84 but sensitivity to PVY strain SON41 and to tobacco etch virus (TEV) strains HAT and CAA10. Variant present in the allele pvr1, haplotype I1, confers an increased resistance to tobacco etch virus (TEV) strains HAT and NW associated with impaired TEV VPg binding and inability to bind 7-methylguanosine-containing mRNA cap. Variant present in the strain cv. SC81, allele pvr2(5), is associated with an increased resistance to potato virus Y (PVY) strains LYE84 and SON41 but sensitivity to tobacco etch virus (TEV) strains HAT and CAA10. Displayed sequence is allele pvr2(+), haplotype B1 found in strains cv. Doux Long des Landes, cv. Yolo Wonder, cv. Flambeau, cv. PI187331, cv. Cuba 3, cv. Bousso 1, cv. Pimiento Morron, cv. H3, cv. Lamu, cv. Bastidon, cv. CDP04928 and cv. Antibois which confers sensitivity to potato virus Y (PVY) strains LYE84 and SON41 and to tobacco etch virus (TEV) strains HAT and CAA10. The allele pvr2(2) correlates with resistance to pepper veinal mottle virus (PVMV), especially when associated with the pvr6 allele of eIF(iso)4E (PubMed:16760413). Plants harboring specific haplotypes couples for eIF4E/eIF(iso)4E are resistant or tolerant to potyvirus such as potato virus Y (PVY) (PubMed:21073716). Belongs to the eukaryotic initiation factor 4E family.