Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Roles of the two lysyl-tRNA synthetases of Escherichia coli: analysis of nucleotide sequences and mutant behavior.

ABSTRACT: The complete nucleotide sequence of lysU, the gene for the heat-inducible lysyl-tRNA synthetase of Escherichia coli, was determined and compared with the published sequence of lysS (herC), the gene for the constitutive lysyl-tRNA synthetase. These unlinked genes were found to be identical over 72% of their lengths. The deduced amino acid sequences of the respective gene products, LysU and LysS, were identical over 85% and similar over 92% of their lengths. Accumulation of high levels of LysU during growth of strains carrying the wild-type allele of lysU on multicopy plasmids had no observable effect on growth or on the synthesis of LysS. A lysU deletion strain was constructed and was shown to grow normally at low temperature (28 degrees C) but poorly at 44 degrees C; the slow growth (45% of normal) at elevated temperature was fully reversed by plasmids bearing wild-type lysU. The implications of these findings for the existence of two aminoacyl-tRNA synthetases for lysine are discussed.

SUBMITTER: Clark RL

PROVIDER: S-EPMC209130 | biostudies-other | 1990 Jun

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Homology of aspartyl- and lysyl-tRNA synthetases.

Project description:The yeast nuclear gene MSD1 coding for mitochondrial aspartyl-tRNA synthetase has been cloned and sequenced. The identity of the gene is confirmed by the following evidence. (i) The primary structure of the protein derived from the gene sequence is similar to that of the yeast cytoplasmic aspartyl-tRNA synthetase. (ii) In situ disruption of MSD1 in a respiratory-competent haploid strain of yeast induces a pleiotropic phenotype consistent with a lesion in mitochondrial protein synthesis. (iii) Mitochondria from a mutant with a disrupted chromosomal copy of MSD1 are unable to acylate mitochondrial aspartyl-tRNA. The primary structures of the cytoplasmic and mitochondrial aspartyl-tRNA synthetases are similar to the yeast cytoplasmic lysyl-tRNA synthetase, suggesting that the two types of synthetases may have a common evolutionary origin. Searches of the current protein banks also have revealed a high degree of sequence similarity of the lysyl-tRNA synthetase to the product of the Escherichia coli herC gene and to the partial sequence of a protein encoded by an unidentified reading frame located adjacent to the E. coli frdA gene. Based on the sequence similarities and the map positions of the herC and frdA loci, we propose herC to be the structural gene of the constitutively expressed lysyl-tRNA synthetase of E. coli and the unidentified reading frame to be the structural gene of the heat-inducible lysyl-tRNA synthetase.

| S-EPMC297767 | biostudies-other

Essentiality Assessment of Cysteinyl and Lysyl-tRNA Synthetases of Mycobacterium smegmatis.

Project description:Discovery of mupirocin, an antibiotic that targets isoleucyl-tRNA synthetase, established aminoacyl-tRNA synthetase as an attractive target for the discovery of novel antibacterial agents. Despite a high degree of similarity between the bacterial and human aminoacyl-tRNA synthetases, the selectivity observed with mupirocin triggered the possibility of targeting other aminoacyl-tRNA synthetases as potential drug targets. These enzymes catalyse the condensation of a specific amino acid to its cognate tRNA in an energy-dependent reaction. Therefore, each organism is expected to encode at least twenty aminoacyl-tRNA synthetases, one for each amino acid. However, a bioinformatics search for genes encoding aminoacyl-tRNA synthetases from Mycobacterium smegmatis returned multiple genes for glutamyl (GluRS), cysteinyl (CysRS), prolyl (ProRS) and lysyl (LysRS) tRNA synthetases. The pathogenic mycobacteria, namely, Mycobacterium tuberculosis and Mycobacterium leprae, were also found to possess two genes each for CysRS and LysRS. A similar search indicated the presence of additional genes for LysRS in gram negative bacteria as well. Herein, we describe sequence and structural analysis of the additional aminoacyl-tRNA synthetase genes found in M. smegmatis. Characterization of conditional expression strains of Cysteinyl and Lysyl-tRNA synthetases generated in M. smegmatis revealed that the canonical aminoacyl-tRNA synthetase are essential, while the additional ones are not essential for the growth of M. smegmatis.

| S-EPMC4721953 | biostudies-literature

Roles of Aminoacyl-tRNA Synthetases in Cancer.

Project description:Aminoacyl-tRNA synthetases (ARSs) catalyze the ligation of amino acids to their cognate transfer RNAs (tRNAs), thus playing an important role in protein synthesis. In eukaryotic cells, these enzymes exist in free form or in the form of multi-tRNA synthetase complex (MSC). The latter contains nine cytoplasmic ARSs and three ARS-interacting multifunctional proteins (AIMPs). Normally, ARSs and AIMPs are regarded as housekeeping molecules without additional functions. However, a growing number of studies indicate that ARSs are involved in a variety of physiological and pathological processes, especially tumorigenesis. Here, we introduce the roles of ARSs and AIMPs in certain cancers, such as colon cancer, lung cancer, breast cancer, gastric cancer and pancreatic cancer. Furthermore, we particularly focus on their potential clinical applications in cancer, aiming at providing new insights into the pathogenesis and treatment of cancer.

| S-EPMC7729087 | biostudies-literature

Control of Escherichia coli lysyl-tRNA synthetase expression by anaerobiosis.

Project description:Escherichia coli lysyl-tRNA synthetase was previously shown to occur as two distinct species encoded by either the lysS or the lysU gene. The expression of one of these genes, lysU, is under the control of cell growth conditions. To study the regulation of lysU, delta lysS strains were constructed. During aerobic growth at 37 degrees C or below, the amount of the lysU product in the cell is so reduced that delta lysS bacteria grow only poorly. The reduced expression of lysU is not related to the steady-state lysyl-tRNA synthetase concentration in the cell, since the expression of a lysU::lacZ fusion is insensitive to the absence of either lysS or lysU or to the addition of a multi-copy plasmid carrying either lysU or lysS. During anaerobic growth in rich medium, the lysU gene becomes strongly expressed and, in cell extracts, the amount of lysyl-tRNA synthetase activity originating from lysU may become seven times greater than the activity originating from lysS. In minimal medium, lysU expression is only slightly induced. Evidence that the sensitivity of lysU expression to anaerobiosis, as well as to low external pH conditions (E. W. Hickey and I. N. Hirshfield, Appl. Environ. Microbiol. 56:1038-1045, 1990), is governed at the level of transcription is provided.

| S-EPMC212583 | biostudies-other

Activities of 20 aminoacyl-tRNA synthetases expressed in a reconstituted translation system in Escherichia coli.

Project description:A significant challenge in the field of in vitro synthetic biology is the construction of a self-reproducing cell-free translation system, which reproduces its components, such as translation proteins, through translation and transcription by itself. As a first step for such construction, in this study we expressed and evaluated the activity of 20 aminoacyl-tRNA synthetases (aaRSs), a major component of a translation system, in a reconstituted translation system (PURE system). We found that 19 aaRS with the exception of phenylalanyl-tRNA synthetase (PheRS) are expressed as soluble proteins and their activities are comparable to those expressed in Escherichia coli . This study provides basic information on the properties of aaRSs expressed in the PURE system, which will be helpful for the future reconstitution of a self-reproducing translation system.

| S-EPMC5668874 | biostudies-literature

Substrate recognition by class I lysyl-tRNA synthetases: a molecular basis for gene displacement.

Project description:Lysyl-tRNA synthetases (LysRSs) are unique amongst the aminoacyl-tRNA synthetases in being composed of unrelated class I and class II enzymes. To allow direct comparison between the two types of LysRS, substrate recognition by class I LysRSs was examined. Genes encoding both an archaeal and a bacterial class I enzyme were able to rescue an Escherichia coli strain deficient in LysRS, indicating their ability to functionally substitute for a class II LysRS in vivo. In vitro characterization showed lysine activation and recognition to be tRNA-dependent, an attribute of several class I, but not class II, aminoacyl-tRNA synthetases. Examination of tRNA recognition showed that class I LysRSs recognize the same elements in tRNALys as their class II counterparts, namely the discriminator base (N73) and the anticodon. This sequence-specific recognition of the same nucleotides in tRNALys by the two unrelated types of enzyme suggests that tRNALys predates at least one of the LysRSs in the evolution of the translational apparatus. The only observed variation in recognition was that the G2.U71 wobble pair of spirochete tRNALys acts as antideterminant for class II LysRS but does not alter class I enzyme recognition. This difference in tRNA recognition strongly favors the use of a class I-type enzyme to aminoacylate particular tRNALys species and provides a molecular basis for the observed displacement of class II by class I LysRSs in certain bacteria.

| S-EPMC15151 | biostudies-literature

Lysyl-tRNA synthetase from Escherichia coli K12. Chromatographic heterogeneity and the lysU-gene product.

Project description:In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5')tetraphospho(5')adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.

| S-EPMC1148498 | biostudies-other

Non-canonical Amino Acid Substrates of E. coli Aminoacyl-tRNA Synthetases.

Project description:In this comprehensive review, I focus on the twenty E. coli aminoacyl-tRNA synthetases and their ability to charge non-canonical amino acids (ncAAs) onto tRNAs. The promiscuity of these enzymes has been harnessed for diverse applications including understanding and engineering of protein function, creation of organisms with an expanded genetic code, and the synthesis of diverse peptide libraries for drug discovery. The review catalogues the structures of all known ncAA substrates for each of the 20 E. coli aminoacyl-tRNA synthetases, including ncAA substrates for engineered versions of these enzymes. Drawing from the structures in the list, I highlight trends and novel opportunities for further exploitation of these ncAAs in the engineering of protein function, synthetic biology, and in drug discovery.

| S-EPMC9651912 | biostudies-literature

Homology of lysS and lysU, the two Escherichia coli genes encoding distinct lysyl-tRNA synthetase species.

Project description:In Escherichia coli, two distinct lysyl-tRNA synthetase species are encoded by two genes: the constitutive lysS gene and the thermoinducible lysU gene. These two genes have been isolated and sequenced. Their nucleotide and deduced amino acid sequences show 79% and 88% identity, respectively. Codon usage analysis indicates the lysS product being more efficiently translated than the lysU one. In addition, the lysS sequence exactly coincides with the sequence of herC, a gene which is part of the prfB-herC operon. In contrast to the recent proposal of Gampel and Tzagoloff (1989, Proc. Natl. Acad. Sci. USA 86, 6023-6027), the lysU sequence is distinct from the open reading frame located adjacent to frdA, although large homologies are shared by these two genes.

| S-EPMC330268 | biostudies-other

Peripheral neuropathy via mutant tRNA synthetases: Inhibition of protein translation provides a possible explanation.

Project description:Recent evidence indicates that inhibition of protein translation may be a common pathogenic mechanism for peripheral neuropathy associated with mutant tRNA synthetases (aaRSs). aaRSs are enzymes that ligate amino acids to their cognate tRNA, thus catalyzing the first step of translation. Dominant mutations in five distinct aaRSs cause Charcot-Marie-Tooth (CMT) peripheral neuropathy, characterized by length-dependent degeneration of peripheral motor and sensory axons. Surprisingly, loss of aminoacylation activity is not required for mutant aaRSs to cause CMT. Rather, at least for some mutations, a toxic-gain-of-function mechanism underlies CMT-aaRS. Interestingly, several mutations in two distinct aaRSs were recently shown to inhibit global protein translation in Drosophila models of CMT-aaRS, by a mechanism independent of aminoacylation, suggesting inhibition of translation as a common pathogenic mechanism. Future research aimed at elucidating the molecular mechanisms underlying the translation defect induced by CMT-mutant aaRSs should provide novel insight into the molecular pathogenesis of these incurable diseases.

| S-EPMC5094542 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data