Disease relevance of gltX

• Two tRNA operons have been found near the gltX gene encoding the glutamyl-tRNA synthetase of Escherichia coli K-12 [1].
• We show that the transcript levels of gltX in Synechococcus depend on nitrogen availability and do not increase with the growth rate, which is at odds with observations from other bacteria [2].
• Glutamyl-tRNA synthetase from Thermus thermophilus HB8. Molecular cloning of the gltX gene and crystallization of the overproduced protein [3].
• In vivo and in vitro processing of the Bacillus subtilis transcript coding for glutamyl-tRNA synthetase, serine acetyltransferase, and cysteinyl-tRNA synthetase [4].
• Co-transcription of Rhizobium meliloti lysyl-tRNA synthetase and glutamyl-tRNA synthetase genes [5].

High impact information on gltX

• Conservative replacement of each histidine and cysteine residue of the 98C-138C segment, respectively, with glutamine (Q) and serine (S), yields variants H129Q, H131Q, H132Q, and C138S (which sustain the growth at 42 degrees C of E. coli JP1449, whose glutamyl-tRNA synthetase is thermosensitive) and C98S, C100S, C125S, and H127Q (which do not) [6].
• A T-box sequence and a rho-independent terminator known to regulate expression of other aminoacyl-tRNA synthetase genes and of some amino acid biosynthetic operons in Bacillus sp., were found between gltX and cysE [7].
• S1 mapping analysis shows that the transcription of gltX is under the control of a sigma A promoter located 43 base pairs upstream of the initiation codon [7].
• The gltX gene encoding the glutamyl-tRNA synthetase of Escherichia coli and adjacent regulatory regions was isolated and sequenced [8].
• Sequence homology between the glutamyl-tRNA synthetase and other aminoacyl-tRNA synthetases of E. coli was found in four segments [8].

Chemical compound and disease context of gltX

• All three enzymes were separated from extracts of the unicellular cyanobacterium Synechocystis sp. PCC 6803, and two of them, glutamyl-tRNA synthetase and GSA aminotransferase, were partially characterized [9].
• 5'-O-[N-(L-glutamyl)-sulfamoyl] adenosine is a potent competitive inhibitor of E. coli glutamyl-tRNA synthetase with respect to glutamic acid (K(i) = 2.8 nM) and is the best inhibitor of this enzyme [10].

Biological context of gltX

• The valU operon containing genes for three identical tRNA(UACVal) and one tRNA(UUULys) (the wild-type allele of supN), is adjacent to gltX and is transcribed from the opposite strand [1].
• The gltX and valU promoters share the same AT-rich and bent upstream region, whose position coincides with the position of the upstream activating sequences of tRNA and rRNA promoters to which they are similar [11].
• A plasmid containing a 2.3-kb insert complemented the temperature-sensitive gltX mutation of Escherichia coli JP1449, and GltX activity was demonstrated [12].
• The amino acid sequence deduced from the nucleotide sequence of the gltX gene was confirmed by mass spectrometry of large peptides derived from the glutamyl-tRNA synthetase [8].
• An open reading frame encoding a putative polypeptide very similar to several lysyl-tRNA synthetases was found 10 nucleotides downstream of Rhizobium meliloti gltX encoding glutamyl-tRNA synthetase [5].

Associations of gltX with chemical compounds

• Neither glutamyl-tRNA synthetase nor GSA aminotransferase activity was affected by hemin concentrations up to 10 and 30 microM, respectively, and neither activity was affected by protochlorophyllide concentrations up to 2 microM [9].
• Conformation change of tRNAGlu in the complex with glutamyl-tRNA synthetase is required for the specific binding of L-glutamate [13].

Other interactions of gltX

• We analyzed the nine mutants genetically and found that they could be classified into three complementation groups, pktA, pktB and pktC, which corresponded to three genes, ileS, gltX and asnS, encoding isoleucyl-, glutamyl- and asparaginyl-tRNA synthetases, respectively [14].

Analytical, diagnostic and therapeutic context of gltX

• The apparent native molecular masses of glutamyl-tRNA synthetase and GSA aminotransferase were determined by gel filtration chromatography to be 63 and 98 kDa, respectively [9].
• The zinc-binding site of Escherichia coli glutamyl-tRNA synthetase is located in the acceptor-binding domain. Studies by extended x-ray absorption fine structure, molecular modeling, and site-directed mutagenesis [6].

References