Mutation from guanine to adenine in 25S rRNA at the position equivalent to E. coli A2058 does not confer erythromycin sensitivity in Sacchromyces cerevisae.
The macrolide erythromycin binds to the large subunit of the prokaryotic ribosome near the peptidyltransferase center (PTC) and inhibits elongation of new peptide chains beyond a few amino acids. Nucleotides A2058 and A2059 (E. coli numbering) in 23S rRNA play a crucial role in the binding of erythromycin, and mutation of nucleotide A2058 confers erythromycin resistance in both gram-positive and gram-negative bacteria. There are high levels of sequence and structural similarity in the PTC of prokaryotic and eukaryotic ribosomes. However, eukaryotic ribosomes are resistant to erythromycin and the presence of a G at the position equivalent to E. coli nucleotide A2058 is believed to be the reason. To test this hypothesis, we introduced a G to A mutation at this position of the yeast Saccharomyces cerevisiae 25S rRNA and analyzed sensitivity toward erythromycin. Neither growth studies nor erythromycin binding assays on mutated yeast ribosomes indicated any erythromycin sensitivity in mutated yeast strains. These results suggest that the identity of nucleotide 2058 is not the only determinant responsible for the difference in erythromycin sensitivity between yeast and prokaryotes.
Bommakanti
Ananth S
AS
Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA.
Lindahl
Lasse
L
Zengel
Janice M
JM
D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics; D004917:Erythromycin / Q000378:metabolism / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity
D017931:DNA Primers; D012329:RNA, Bacterial; D012331:RNA, Fungal; D012335:RNA, Ribosomal; C065039:RNA, ribosomal, 25S; D004917:Erythromycin