A gene encoding arginyl-tRNA synthetase is located in the upstream region of the lysA gene in Brevibacterium lactofermentum: regulation of argS-lysA cluster expression by arginine (original) (raw)
Related papers
European Journal of Biochemistry, 1976
The behaviour of arginyl-tRNA synthetase (EC 6.1.1.19) in the presence of the arginine biosynthetic precursors, argininosuccinate, ornithine and citrulline, was studied in several Escherichia coli K12 strains and in E. coli W. The results of kinetic measurements with partially purified extracts indicate that the arginyl-tRNA synthetase of E. coli is not inhibited by the arginine precursors. The apparent affinity constant K,, for arginine of the K12 enzyme is about 3.4 pM in the absence and in the presence of these precursors, whereas the W enzyme exhibited an apparently slightly lowered K, and a decreased ['4C]arginyl-tRNA equilibrium level in the presence of argininosuccinate. This however was shown to be due to isotopic dilution of [14C]arginine by non-radioactive amino acid formed from argininosuccinate by argininosuccinate lyase (EC 4.3.2.1) contaminating the synthetase preparation. This finding emphasizes the necessity of using pure arginyl-tRNA synthetase in order to study the possible regulatory involvement of this enzyme in the control of the arginine regulon in vitro.
Regulation of biosynthesis of aminoacyl-tRNA synthetases and of tRNA in Escherichia coli
Journal of Molecular Biology, 1977
Spontaneous revertants of a temperaturesensitive Escherichia coli strain harboring a thermolabile leucyl-tRNA synthetase and seryl-tRNA synthetase were selected for growth at 40 ° C. Among these, strains were found with increased levels of both thermolabile synthetases. Two distinct genetic loci were found responsible for enzyme overproduction, leuR, located near xyl, causes elevated levels of leucyl-tRNA synthetase; while serR, located near leu, causes elevated levels of seryl-tRNA synthetase.
L-Arginine recognition by yeast arginyl-tRNA synthetase
The EMBO Journal, 1998
The crystal structure of arginyl-tRNA synthetase (ArgRS) from Saccharomyces cerevisiae, a class I aminoacyl-tRNA synthetase (aaRS), with L-arginine bound to the active site has been solved at 2.75 Å resolution and refined to a crystallographic R-factor of 19.7%. ArgRS is composed predominantly of α-helices and can be divided into five domains, including the class I-specific active site. The N-terminal domain shows striking similarity to some completely unrelated proteins and defines a module which should participate in specific tRNA recognition. The C-terminal domain, which is the putative anticodon-binding module, displays an all-α-helix fold highly similar to that of Escherichia coli methionyl-tRNA synthetase. While ArgRS requires tRNA Arg for the first step of the aminoacylation reaction, the results show that its presence is not a prerequisite for L-arginine binding. All H-bond-forming capability of L-arginine is used by the protein for the specific recognition. The guanidinium group forms two salt bridge interactions with two acidic residues, and one H-bond with a tyrosine residue; these three residues are strictly conserved in all ArgRS sequences. This tyrosine is also conserved in other class I aaRS active sites but plays several functional roles. The ArgRS structure allows the definition of a new framework for sequence alignments and subclass definition in class I aaRSs.
Molecular Biology, 2005
The formation of alternative RNA structures in response to external factors is an important mechanism regulating the expression of bacterial genes. Comparison of the 5'-leader gene regions revealed conserved RNA structures. Attenuating regulation was predicted for the tryptophan and cysteine biosynthesis operons. An element forming a conserved secondary structure in RNA was found upstream of leu A and termed LEU. Translational regulation involving the T-box was predicted for ile S.
Journal of Biological Chemistry
The DNA nucleotide sequence of the v d S gene encoding valyl-tRNA synthetase of Escherichia coli has been determined. The deduced primary structure of valyl-tRNA synthetase was compared to the primary sequences of the known aminoacyl-tRNA synthetases of yeast and bacteria. Significant homology was detected between valyl-tRNA synthetase of E. coli and other known branched-chain aminoacyl-tRNA synthetases. In pairwise comparisons the highest level of homology was detected between the homologous valyl-tRNA synthetases of yeast and E. coli, with an observed 41% direct identity overall. Comparisons between the valyl-and isoleucyl-tRNA synthetases of E. coli yielded the highest level of homology detected between heterologous enzymes (19.2% direct identity overall). An alignment is presented between the three branchedchain aminoacyl-tRNA synthetases (valyl-and isoleucyl-tRNA synthetases of E. coli and yeast mitochondrial leucyl-tRNA synthetase) illustrating the close relatedness of these enzymes. These results give credence to the supposition that the branched-chain aminoacyl-tRNA synthetases along with methionyl-tRNA synthetase form a family of genes within the aminoacyl-tRNA synthetases that evolved from a common ancestral progenitor gene.
Cloning of the Glutamyl-tRNA Synthetase (gltX) Gene from Pseudomonas aeruginosa
1999
The glutamyl-tRNA synthetase (gltX) gene from Pseudomonas aeruginosa was identified. A plasmid containing a 2.3-kb insert complemented the temperature-sensitive gltX mutation of Escherichia coli JP1449, and GltX activity was demonstrated. The inferred amino acid sequence of this gene showed 50.6% identity with GltX from Rhizobium meliloti.
Methods, 2008
Here we describe the many applications of acid urea polyacrylamide gel electrophoresis (acid urea PAGE) followed by Northern blot analysis to studies of tRNAs. Acid urea PAGE allows the electrophoretic separation of different forms of a tRNA, discriminated by changes in bulk, charge, and/or conformation that are brought about by aminoacylation, formylation, or modification of a tRNA. Among the examples described are (i) analysis of the effect of mutations in the Escherichia coli initiator tRNA on its aminoacylation and formylation; (ii) evidence of orthogonality of suppressor tRNAs in mammalian cells and yeast; (iii) analysis of aminoacylation specificity of an archaeal prolyl-tRNA synthetase that can aminoacylate archaeal tRNA Pro with cysteine, but does not aminoacylate archaeal tRNA Cys with cysteine; (iv) identification and characterization of the AUAdecoding minor tRNA Ile in archaea; and (v) evidence that the archaeal minor tRNA Ile contains a modified base in the wobble position different from lysidine found in the corresponding eubacterial tRNA.