The translational function of nucleotide C1054 in the small subunit rRNA is conserved throughout evolution: genetic evidence in yeast.
Mutations at position C1054 of 16S rRNA have previously been shown to cause translational suppression in Escherichia coli. To examine the effects of similar mutations in a eukaryote, all three possible base substitutions and a base deletion were generated at the position of Saccharomyces cerevisiae 18S rRNA corresponding to E. coli C1054. In yeast, as in E. coli, both C1054A (rdn-1A) and C1054G (rdn-1G) caused dominant nonsense suppression. Yeast C1054U (rdn-1T) was a recessive antisuppressor, while yeast C1054-delta (rdn-1delta) led to recessive lethality. Both C1054U and two previously described yeast 18S rRNA antisuppressor mutations, G517A (rdn-2) and U912C (rdn-4), inhibited codon-nonspecific suppression caused by mutations in eukaryotic release factors, sup45 and sup35. However, among these only C1054U inhibited UAA-specific suppressions caused by a UAA-decoding mutant tRNA-Gln (SLT3). Our data implicate eukaryotic C1054 in translational termination, thus suggesting that its function is conserved throughout evolution despite the divergence of nearby nucleotide sequences.
Chernoff
Y O
YO
Department of Biological Sciences, University of Illinois Molecular Biology Research Facility, Laboratory for Molecular Biology, Chicago 60607, USA.
Newnam
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GP
Liebman
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SW
D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D016153:Genes, Suppressor; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012331:RNA, Fungal / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000737:chemistry*; D012351:RNA, Transfer, Gln / Q000235:genetics; D012441:Saccharomyces cerevisiae; D013329:Structure-Activity Relationship
D017931:DNA Primers; D012331:RNA, Fungal; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S; D012351:RNA, Transfer, Gln