9Q75
Crystal structure of T. cruzi EIF4E5 in complex with EIF4G1 peptide and cap-4.
Summary for 9Q75
| Entry DOI | 10.2210/pdb9q75/pdb |
| Descriptor | Putative Eukaryotic translation initiation factor 4E type 5, Eukaryotic translation initiation factor 4 gamma 1, SULFATE ION, ... (5 entities in total) |
| Functional Keywords | translation initiation factor, eif4e family, eif4e5, eif4g1, cap-4, translation |
| Biological source | Trypanosoma cruzi Dm28c More |
| Total number of polymer chains | 6 |
| Total formula weight | 89363.43 |
| Authors | |
| Primary citation | Penteado, R.F.,Vichier-Guerre, S.,da Silva Pereira, B.M.,Dugue, L.,Guerra Slompo, E.P.,Assuncao de Matos, T.R.,Pochet, S.,Zanchin, N.I.T.,Guimaraes, B.G. Selective eIF4E-eIF4G Pairing and Cap-4 Recognition Mechanisms in Trypanosomatids: Insights From EIF4E5-EIF4G1 and EIF4E6-EIF4G5 Complexes. J.Mol.Biol., 438:169550-169550, 2026 Cited by PubMed Abstract: Translation initiation in eukaryotes is a highly regulated process involving the assembly of several transient protein complexes. A key step in this process is recognition of the mRNA 5' cap structure by the initiation factor eIF4E, a core component of the eIF4F complex. In trypanosomatids, this mechanism diverges from canonical eukaryotic systems, featuring five distinct eIF4F-like complexes formed through specific pairings of eIF4E and eIF4G homologs. Additionally, trypanosomatid mRNAs exhibit a unique hypermethylated cap-4 structure at the 5' end. To elucidate the molecular basis of selective eIF4E-eIF4G interactions and the modulation of cap binding upon eIF4G engagement, we determined high-resolution crystal structures of EIF4E5-EIF4G1 complexes from Trypanosoma brucei and T. cruzi, and the EIF4E6-EIF4G5 complex from T. cruzi. These structural studies, supported by biophysical analyses in the presence and absence of a cap-4 analog, reveal key determinants of cap recognition associated with cap-4 structural flexibility and plasticity in the cap-binding pockets. We observe conformational rearrangements upon eIF4G binding and propose a relationship between these structural changes and increased cap-4 affinity. In addition, comparative structural analysis of the EIF4E5-EIF4G1 and EIF4E6-EIF4G5 complexes offers atomic-level insights into the molecular determinants of specificity that govern selective eIF4E-eIF4G pairings in trypanosomatids. PubMed: 41265746DOI: 10.1016/j.jmb.2025.169550 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.77 Å) |
Structure validation
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