EIF1

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Protein-coding gene in the species Homo sapiens

title: "EIF1" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public description: "Protein-coding gene in the species Homo sapiens" topic_path: "uncategorized" source: "https://en.wikipedia.org/wiki/EIF1" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Protein-coding gene in the species Homo sapiens ::

Eukaryotic translation initiation factor 1 (eIF1) is a protein that in humans is encoded by the EIF1 gene. It is related to yeast SUI1.

eIF1 interacts with the eukaryotic small (40S) ribosomal subunit and eIF3, and is a component of the 43S preinitiation complex (PIC). eIF1 and eIF1A bind cooperatively to the 40S to stabilize an "open" conformation of the preinitiation complex (PIC) during eukaryotic translation initiation. eIF1 binds to a region near the ribosomal P-site in the 40S subunit and functions in a manner similar to the structurally related bacterial counterpart IF3.

Structure

eIF1's structure was first determined in 1999 by solution-state NMR spectroscopy, which revealed that it consists of a five-stranded beta-sheet which is sided by two alpha-helices. Crystallographic experiments showed that eIF1 is located at the P-site of the small ribosomal subunit, binding to the 18S rRNA with a basic surface. To date, a number of cryo-EM structures have been solved that include eIF1 in the context of various translation initiation complexes.

Function

In eukaryotic cells, translation initiation on an mRNA involves scanning of the mRNA by the 43S pre-initiation complex in search of the translation initiation start codon. Accurate identification of the start codon is very important, as other translation start sites may lead to the production of defect proteins. A codon is detected as a start codon by interaction with the tRNA's anticodon that is positioned in the P-site of the small ribosomal subunit, which leads to closing of the pre-initiation complex. eIF1 is positioned on the small ribosomal subunit such that it blocks the closure of the pre-initiation complex. It thereby aids in selecting the correct start codon, since only the correct codon-anticodon interaction provides enough energy to displace eIF1 and thus close the pre-initiation complex.

References

References

  1. (January 1994). "Expressed sequence tags identify a human isolog of the suil translation initiation factor". Biochemical and Biophysical Research Communications.
  2. (June 1999). "Cloning and characterization of a human genotoxic and endoplasmic reticulum stress-inducible cDNA that encodes translation initiation factor 1(eIF1(A121/SUI1))". The Journal of Biological Chemistry.
  3. "Entrez Gene: EIF1 eukaryotic translation initiation factor 1".
  4. (June 2012). "A mechanistic overview of translation initiation in eukaryotes". Nature Structural & Molecular Biology.
  5. (July 2015). "Quantitative studies of mRNA recruitment to the eukaryotic ribosome". Biochimie.
  6. (May 1999). "Structure and interactions of the translation initiation factor eIF1". The EMBO Journal.
  7. (February 2011). "Crystal structure of the eukaryotic 40S ribosomal subunit in complex with initiation factor 1". Science.
  8. (January 2025). "Structural basis for translational control by the human 48S initiation complex". Nature Structural & Molecular Biology.
  9. (August 2024). "Human tumor suppressor protein Pdcd4 binds at the mRNA entry channel in the 40S small ribosomal subunit". Nature Communications.
  10. (October 2024). "Structural basis of AUC codon discrimination during translation initiation in yeast". Nucleic Acids Research.
  11. (August 2017). "Structural Insights into the Mechanism of Scanning and Start Codon Recognition in Eukaryotic Translation Initiation". Trends in Biochemical Sciences.
  12. (October 2014). "Structural changes enable start codon recognition by the eukaryotic translation initiation complex". Cell.
  13. (May 2018). "eIF1 Loop 2 interactions with Met-tRNAi control the accuracy of start codon selection by the scanning preinitiation complex". Proceedings of the National Academy of Sciences of the United States of America.
  14. "EIF1 - Eukaryotic translation initiation factor 1 - Homo sapiens (Human) - EIF1 gene & protein".

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