Ternatin and improved synthetic variants kill cancer cells by targeting the elongation factor-1A ternary complex

Elife. 2015 Dec 10;4:e10222. doi: 10.7554/eLife.10222.


Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1A·GTP·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products.

Keywords: biochemistry; cancer; cell biology; cyclic peptide; elongation factor-1A; human; natural product; protein synthesis; target identification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / pharmacology*
  • Cell Death*
  • Cell Line, Tumor
  • Drug Resistance
  • Guanosine Triphosphate / metabolism
  • Humans
  • Mutant Proteins / antagonists & inhibitors
  • Mutant Proteins / genetics
  • Mutation
  • Peptide Elongation Factor 1 / antagonists & inhibitors*
  • Peptide Elongation Factor 1 / genetics
  • Peptides, Cyclic / chemical synthesis
  • Peptides, Cyclic / pharmacology*
  • Protein Binding
  • RNA, Transfer / metabolism


  • Antineoplastic Agents
  • Mutant Proteins
  • Peptide Elongation Factor 1
  • Peptides, Cyclic
  • ternatin heptapeptide
  • Guanosine Triphosphate
  • RNA, Transfer