title: Species-specific inhibition of fungal protein synthesis by sordarin: identification of a sordarin-specificity region in eukaryotic elongation factor 2.
abstract: The sordarin class of natural products selectively inhibits fungal protein synthesis by impairing the function of eukaryotic elongation factor 2 (eEF2). Mutations in Saccharomyces cerevisiae eEF2 or the ribosomal stalk protein rpP0 can confer resistance to sordarin, although eEF2 is the major determinant of sordarin specificity. It has been shown previously that sordarin specifically binds S. cerevisiae eEF2 while there is no detectable binding to eEF2 from plants or mammals, despite the high level of amino acid sequence conservation among these proteins. In both whole-cell assays and in vitro translation assays, the efficacy of sordarin varies among different species of pathogenic fungi. To investigate the basis of sordarin's fungal selectivity, eEF2 has been cloned and characterized from several sordarin-sensitive and -insensitive fungal species. Results from in vivo expression of Candida species eEF2s in S. cerevisiae and in vitro translation and growth inhibition assays using hybrid S. cerevisiae eEF2 proteins demonstrate that three amino acid residues within eEF2 account for the selectivity of this class of compounds. It is also shown that the corresponding residues at these positions in human eEF2 are sufficient to confer sordarin insensitivity to S. cerevisiae identical to that observed with mammalian eEF2.
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Mythili
authors.initials: M
authors.lastname: Shastry
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nielsen
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Theresa
authors.initials: T
authors.lastname: Ku
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Ming-Jo
authors.initials: MJ
authors.lastname: Hsu
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Paul
authors.initials: P
authors.lastname: Liberator
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Anderson
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Dennis
authors.initials: D
authors.lastname: Schmatz
authors.affiliation: Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Justice
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000096:biosynthesis; D006801:Humans; D007192:Indenes; D008969:Molecular Sequence Data; D020652:Peptide Elongation Factor 2 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D007192:Indenes; D020652:Peptide Elongation Factor 2; C003329:sordarin