Functional interaction between tRNA2Gly2 at the ribosomal P-site and RF1 during termination at UAG.
The glycine codons GGA or GGG, on the 5' side of stop codons UAG and UGA, are associated with a uniquely low termination efficiency in Escherichia coli, as compared to other codons, including the two glycine codons GGU and GGC. In contrast to the wild-type strain, all four glycine codons have a similar effect on termination at UAG in a strain with a mutant release factor 1 (RF1). Thus, these two glycine codon pairs, when present at the ribosomal P-site, affect termination efficiency of mutant or wild-type RF1 at UAG differently. If reading of GGA/G by tRNAGly2 is eliminated in the RF1 wild-type strain and replaced by a mutant form of tRNAGly3, termination efficiency is increased to the same level as for GGU/C, normally read by tRNAGly3. The results suggest an unusual interaction between the P-site tRNAGly2 and wild-type RF1 at the ribosomal A-site that is not present with mutant RF1.
Zhang
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S
Department of Microbiology, Stockholm University, Stockholm, S-106 91, Sweden.
Rydén-Aulin
M
M
Isaksson
L A
LA
D018388:Codon, Terminator / Q000235:genetics*; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005998:Glycine / Q000235:genetics; D009154:Mutation; D010454:Peptide Termination Factors / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D012353:RNA, Transfer, Gly / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism*
D018388:Codon, Terminator; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; D010454:Peptide Termination Factors; D012353:RNA, Transfer, Gly; C489005:prfA protein, E coli; D005998:Glycine