New targets for antivirals: the ribosomal A-site and the factors that interact with it.
Many viruses use programmed -1 ribosomal frameshifting to ensure the correct ratio of viral structural to enzymatic proteins. Alteration of frameshift efficiencies changes these ratios, in turn inhibiting viral particle assembly and virus propagation. Previous studies determined that anisomycin, a peptidyl transferase inhibitor, specifically inhibited -1 frameshifting and the ability of yeast cells to propagate the L-A and M(1) dsRNA viruses (J. D. Dinman, M. J. Ruiz-Echevarria, K. Czaplinski, and S. W. Peltz, 1997, Proc. Natl. Acad. Sci. USA 94, 6606-6611). Here we show that preussin, a pyrollidine that is structurally similar to anisomycin (R. E. Schwartz, J. Liesch, O. Hensens, L. Zitano, S. Honeycutt, G. Garrity, R. A. Fromtling, J. Onishi, and R. Monaghan, 1988. J. Antibiot. (Tokyo) 41, 1774--1779), also inhibits -1 programmed ribosomal frameshifting and virus propagation by acting at the same site or through the same mechanism as anisomycin. Since anisomycin is known to assert its effect at the ribosomal A-site, we undertook a pharmacogenetic analysis of mutants of trans-acting eukaryotic elongation factors (eEFs) that function at this region of the ribosome. Among mutants of eEF1A, a correlation is observed between resistance/susceptibility profiles to preussin and anisomycin, and these in turn correlate with programmed -1 ribosomal frameshifting efficiencies and killer virus phenotypes. Among mutants of eEF2, the extent of resistance to preussin correlates with resistance to sordarin, an eEF2 inhibitor. These results suggest that structural features associated with the ribosomal A-site and with the trans-acting factors that interact with it may present a new set of molecular targets for the rational design of antiviral compounds.
Department of Molecular Genetics and Microbiology, UMDNJ/Rutgers Universities, UMDNJ Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854, USA.
Terri
T
Goss Kinzy
Jason W
JW
Harger
Anne
A
Carr-Schmid
Jane
J
Kwon
Mythili
M
Shastry
Michael
M
Justice
Jonathan D
JD
Dinman
D000841:Anisomycin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D000998:Antiviral Agents / Q000138:chemical synthesis / Q000737:chemistry*; D015195:Drug Design; D016368:Frameshift Mutation / Q000187:drug effects; D005838:Genotype; D007700:Kinetics; D008958:Models, Molecular; D020653:Peptide Elongation Factor G / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D012269:Ribosomal Proteins / Q000187:drug effects*; D012270:Ribosomes / Q000187:drug effects*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000821:virology*; D013329:Structure-Activity Relationship; D013997:Time Factors
D000998:Antiviral Agents; D020653:Peptide Elongation Factor G; D012269:Ribosomal Proteins; C058280:preussin; D000841:Anisomycin; C016700:ribosomal protein L7-L12