Species-specific inhibition of fungal protein synthesis by sordarin: identification of a sordarin-specificity region in eukaryotic elongation factor 2.
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.
Shastry
Mythili
M
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Nielsen
Jennifer
J
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Ku
Theresa
T
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Hsu
Ming-Jo
MJ
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Liberator
Paul
P
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Anderson
Jennifer
J
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Schmatz
Dennis
D
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
Justice
Michael C
MC
Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1.
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
D000935:Antifungal Agents; D005656:Fungal Proteins; D007192:Indenes; D020652:Peptide Elongation Factor 2; C003329:sordarin