TY - JOUR
T1 - Alternative pathways for editing non-cognate amino acids by aminoacyl-tRNA synthetases
AU - Jakubowski, Hieronim
AU - R.fersht, Alan
N1 - Funding Information:
ACKNOWLEDGEMENTS This work was supported by an EMBO Short-Term Fellowship tenable at Imperial College (H.J.), MRC Programme Grant G977/985 and Polish Academy of Science Project 09.7.1.
PY - 1981/7/10
Y1 - 1981/7/10
N2 - Evidence is presented that the editing mechanisms of aminoacyl-tRNA synthetases operate by two alternative pathways: pre-transfer, by hydrolysis of the non-cognate aminoacyl adenylate; post-transfer, by hydrolysis of the mischarged tRNA. The methionyl-tRNA synthetases from Escherichia coli and Bacillus stearothermophilus and isoleucyl-tRNA synthetase from E. coli, for example, are shown to reject misactivated homocysteine rapidly by the pretransfer route. A novel feature of this reaction is that homocysteine thiolactone is formed by the facile cyclisation of the homocysteinyl adenylate. Valyl-tRNA synthetases, on the other hand, reject the more readily activated non-cognate amino acids by primarily the post-transfer route. The features governing the choice of pathway are discussed.
AB - Evidence is presented that the editing mechanisms of aminoacyl-tRNA synthetases operate by two alternative pathways: pre-transfer, by hydrolysis of the non-cognate aminoacyl adenylate; post-transfer, by hydrolysis of the mischarged tRNA. The methionyl-tRNA synthetases from Escherichia coli and Bacillus stearothermophilus and isoleucyl-tRNA synthetase from E. coli, for example, are shown to reject misactivated homocysteine rapidly by the pretransfer route. A novel feature of this reaction is that homocysteine thiolactone is formed by the facile cyclisation of the homocysteinyl adenylate. Valyl-tRNA synthetases, on the other hand, reject the more readily activated non-cognate amino acids by primarily the post-transfer route. The features governing the choice of pathway are discussed.
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U2 - 10.1093/nar/9.13.3105
DO - 10.1093/nar/9.13.3105
M3 - Article
C2 - 7024910
AN - SCOPUS:0019877050
VL - 9
SP - 3105
EP - 3117
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 13
ER -