| Literature DB >> 6317866 |
M Springer, M Trudel, M Graffe, J Plumbridge, G Fayat, J F Mayaux, C Sacerdot, S Blanquet, M Grunberg-Manago.
Abstract
The two subunits of phenylalanyl-tRNA synthetase are made from two adjacent, cotranscribed genes that constitute the pheS,T operon. Three different fusions between pheS,T and lac genes were constructed in order to study the regulation of the pheS,T operon in vivo. We show, using these fusions, that phenylalanyl-tRNA synthetase transcription is derepressed when the level of aminoacylated tRNAPhe is lowered by mutational alteration of the synthetase. The pheS,T operon is also derepressed in strains carrying a trpX mutation. The gene trpX codes for an enzyme that modifies both tRNATrp and tRNAPhe and a mutation in that gene causes derepression of the trp and pheA operons, both of which are controlled by attenuation. The in vivo features of the regulation of pheS,T expression described here in correlation with the DNA sequence and in vitro transcription results described in the accompanying paper by Fayat et al. indicate that phenylalanyl-tRNA synthetase is controlled by attenuation in a way analogous to several amino acid biosynthetic operons.Entities:
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Year: 1983 PMID： 6317866 DOI： 10.1016/0022-2836(83)90093-1
Source DB: PubMed Journal: J Mol Biol ISSN： 0022-2836 Impact factor: 5.469