Abstract
An unusual, spontaneously arising mutant of Escherichia coli tRNA2Arg has been deduced to have two extra nucleotides in its anticodon loop and a duplication of ten nucleotide residues in the TFC loop. This conclusion is based on its gene sequence, Northern blot analysis of isolated tRNA and the size of the in vitro -processed tRNA product. In vitro analyses showed that the mutant precursor is processed normally, albeit inefficiently, to a mature tRNA species 12 nucleotides longer than the wild-type. In addition, the mature tRNA functions as a frameshift suppressor in vivo. Several related mutants with more conservative changes within the gene sequence were similarly shown to be accurately processed, albeit with varying degrees of efficiency less than that of the wild-type. These results indicate that in spite of the high degree of evolutionary conservation of the tertiary structure of tRNAs, and the fact that no such naturally-occurring variant has been found, a greatly enlarged tRNA is capable of functioning in protein synthesis. The data also indicate that recognition sites for correct processing of precursor tRNAs may be unexpectedly tolerant of unusual context, and may depend on some specific features of the tertiary structure rather than the overall structure for accurate processing.
| Original language | English |
|---|---|
| Pages (from-to) | 1369-1376 |
| Number of pages | 8 |
| Journal | Journal of Molecular Biology |
| Volume | 235 |
| Issue number | 5 |
| State | Published - Dec 1 1994 |
| Externally published | Yes |
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Keywords
- Frameshift suppression
- Ribonucleases
- TFC arm
- tRNA processing
ASJC Scopus subject areas
- Virology
Cite this
A functional mutant of tRNA2Arg with ten extra nucleotides in its TFC arm. / Tuohy, Thérèse M F; Li, Zhongwei; Atkins, John F.; Deutscher, Murray P.
In: Journal of Molecular Biology, Vol. 235, No. 5, 01.12.1994, p. 1369-1376.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A functional mutant of tRNA2Arg with ten extra nucleotides in its TFC arm
AU - Tuohy, Thérèse M F
AU - Li, Zhongwei
AU - Atkins, John F.
AU - Deutscher, Murray P
PY - 1994/12/1
Y1 - 1994/12/1
N2 - An unusual, spontaneously arising mutant of Escherichia coli tRNA2Arg has been deduced to have two extra nucleotides in its anticodon loop and a duplication of ten nucleotide residues in the TFC loop. This conclusion is based on its gene sequence, Northern blot analysis of isolated tRNA and the size of the in vitro -processed tRNA product. In vitro analyses showed that the mutant precursor is processed normally, albeit inefficiently, to a mature tRNA species 12 nucleotides longer than the wild-type. In addition, the mature tRNA functions as a frameshift suppressor in vivo. Several related mutants with more conservative changes within the gene sequence were similarly shown to be accurately processed, albeit with varying degrees of efficiency less than that of the wild-type. These results indicate that in spite of the high degree of evolutionary conservation of the tertiary structure of tRNAs, and the fact that no such naturally-occurring variant has been found, a greatly enlarged tRNA is capable of functioning in protein synthesis. The data also indicate that recognition sites for correct processing of precursor tRNAs may be unexpectedly tolerant of unusual context, and may depend on some specific features of the tertiary structure rather than the overall structure for accurate processing.
AB - An unusual, spontaneously arising mutant of Escherichia coli tRNA2Arg has been deduced to have two extra nucleotides in its anticodon loop and a duplication of ten nucleotide residues in the TFC loop. This conclusion is based on its gene sequence, Northern blot analysis of isolated tRNA and the size of the in vitro -processed tRNA product. In vitro analyses showed that the mutant precursor is processed normally, albeit inefficiently, to a mature tRNA species 12 nucleotides longer than the wild-type. In addition, the mature tRNA functions as a frameshift suppressor in vivo. Several related mutants with more conservative changes within the gene sequence were similarly shown to be accurately processed, albeit with varying degrees of efficiency less than that of the wild-type. These results indicate that in spite of the high degree of evolutionary conservation of the tertiary structure of tRNAs, and the fact that no such naturally-occurring variant has been found, a greatly enlarged tRNA is capable of functioning in protein synthesis. The data also indicate that recognition sites for correct processing of precursor tRNAs may be unexpectedly tolerant of unusual context, and may depend on some specific features of the tertiary structure rather than the overall structure for accurate processing.
KW - Frameshift suppression
KW - Ribonucleases
KW - TFC arm
KW - tRNA processing
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UR - http://www.scopus.com/inward/citedby.url?scp=0028181447&partnerID=8YFLogxK
M3 - Article
VL - 235
SP - 1369
EP - 1376
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 5
ER -