Identification of elongation factor G as the conserved cellular target of argyrin B.

Abstract

Argyrins, produced by myxobacteria and actinomycetes, are cyclic octapeptides with antibacterial and antitumor activity. Here, we identify elongation factor G (EF-G) as the cellular target of argyrin B in bacteria, via resistant mutant selection and whole genome sequencing, biophysical binding studies and crystallography. Argyrin B binds a novel allosteric pocket in EF-G, distinct from the known EF-G inhibitor antibiotic fusidic acid, revealing a new mode of protein synthesis inhibition. In eukaryotic cells, argyrin B was found to target mitochondrial elongation factor G1 (EF-G1), the closest homologue of bacterial EF-G. By blocking mitochondrial translation, argyrin B depletes electron transport components and inhibits the growth of yeast and tumor cells. Further supporting direct inhibition of EF-G1, expression of an argyrin B-binding deficient EF-G1 L693Q variant partially rescued argyrin B-sensitivity in tumor cells. In summary, we show that argyrin B is an antibacterial and cytotoxic agent that inhibits the evolutionarily conserved target EF-G, blocking protein synthesis in bacteria and mitochondrial translation in yeast and mammalian cells.

• Authors: Beat Nyfeler, Dominic Hoepfner, Deborah Palestrant, Christina A Kirby, Lewis Whitehead, Robert Yu, Gejing Deng, Ruth E Caughlan, Angela L Woods, Adriana K Jones, S Whitney Barnes, John R Walker, Swann Gaulis, Ervan Hauy, Saskia M Brachmann, Philipp Krastel, Christian Studer, Ralph Riedl, David Estoppey, Thomas Aust, N Rao Movva, Zuncai Wang, Michael Salcius, Gregory A Michaud, Gregory McAllister, Leon O Murphy, John A Tallarico, Christopher J Wilson, Charles R Dean
• Journal: PloS one (PLoS One) Vol. 7 Issue 9 Pg. e42657 ( 2012) ISSN: 1932-6203 [Electronic] United States
• PMID: 22970117 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Mitochondrial Proteins
• Mutant Proteins
• Oligopeptides
• Peptide Elongation Factor G
• argyrin B

Topics

• Allosteric Site
• Amino Acid Sequence
• Animals
• Burkholderia (drug effects)
• Cell Line, Tumor
• Conserved Sequence
• Crystallography, X-Ray
• Humans
• Mammals
• Microbial Sensitivity Tests
• Mitochondrial Proteins (metabolism)
• Molecular Sequence Data
• Mutant Proteins (chemistry, metabolism)
• Oligopeptides (chemistry, metabolism, pharmacology)
• Peptide Elongation Factor G (antagonists & inhibitors, chemistry, metabolism)
• Protein Binding (drug effects)
• Pseudomonas aeruginosa (drug effects)
• Saccharomyces cerevisiae (metabolism)
• Sequence Homology, Amino Acid