scholarly journals Valyl-tRNA synthetase gene of Escherichia coli K12. Primary structure and homology within a family of aminoacyl-TRNA synthetases.

1988 ◽  
Vol 263 (2) ◽  
pp. 868-877
Author(s):  
J D Heck ◽  
G W Hatfield
Keyword(s):  
Escherichia Coli ◽  
Primary Structure ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
Escherichia Coli K12 ◽  
Aminoacyl Trna Synthetases

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

1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Activity Ratio ◽  
Deae Cellulose ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
E Coli ◽  
Aminoacyl Trna Synthetases

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.

scholarly journals Structure-guided enhancement of selectivity of chemical probe inhibitors targeting bacterial seryl-tRNA synthetase

2019 ◽  
Author(s):  
Ricky Cain ◽  
Ramya Salimraj ◽  
Avinash S. Punekar ◽  
Dom Bellini ◽  
Colin W. G. Fishwick ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Discovery ◽  
Bacterial Species ◽  
Trna Synthetase ◽  
Human Homologue ◽  
X Ray ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases ◽  
Chemical Inhibition ◽  
Selective Chemical

AbstractAminoacyl-tRNA synthetases are ubiquitous and essential enzymes for protein synthesis and also a variety of other metabolic processes, especially in bacterial species. Bacterial aminoacyl-tRNA synthetases represent attractive and validated targets for antimicrobial drug discovery if issues of prokaryotic versus eukaryotic selectivity and antibiotic resistance generation can be addressed. We have determined high resolution X-ray crystal structures of the Escherichia coli and Staphylococcus aureus seryl-tRNA synthetases in complex with aminoacyl adenylate analogues and applied a structure-based drug discovery approach to explore and identify a series of small molecule inhibitors that selectively inhibit bacterial seryl-tRNA synthetases with greater than two orders of magnitude compared to their human homologue, demonstrating a route to selective chemical inhibition of these bacterial targets.

scholarly journals Inhibitory mechanism of reveromycin A at the tRNA binding site of a class I synthetase

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bingyi Chen ◽  
Siting Luo ◽  
Songxuan Zhang ◽  
Yingchen Ju ◽  
Qiong Gu ◽  
...  
Keyword(s):  
Binding Site ◽  
Catalytic Domain ◽  
Trna Synthetase ◽  
Rational Drug Design ◽  
Class I ◽  
Binding Assays ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases ◽  
Rational Drug ◽  
Trna Binding

AbstractThe polyketide natural product reveromycin A (RM-A) exhibits antifungal, anticancer, anti-bone metastasis, anti-periodontitis and anti-osteoporosis activities by selectively inhibiting eukaryotic cytoplasmic isoleucyl-tRNA synthetase (IleRS). Herein, a co-crystal structure suggests that the RM-A molecule occupies the substrate tRNAIle binding site of Saccharomyces cerevisiae IleRS (ScIleRS), by partially mimicking the binding of tRNAIle. RM-A binding is facilitated by the copurified intermediate product isoleucyl-adenylate (Ile-AMP). The binding assays confirm that RM-A competes with tRNAIle while binding synergistically with l-isoleucine or intermediate analogue Ile-AMS to the aminoacylation pocket of ScIleRS. This study highlights that the vast tRNA binding site of the Rossmann-fold catalytic domain of class I aminoacyl-tRNA synthetases could be targeted by a small molecule. This finding will inform future rational drug design.

A naturally occurring nonapeptide functionally compensates for the CP1 domain of leucyl-tRNA synthetase to modulate aminoacylation activity

2012 ◽  
Vol 443 (2) ◽  
pp. 477-484 ◽  
Author(s):  
Min Tan ◽  
Wei Yan ◽  
Ru-Juan Liu ◽  
Meng Wang ◽  
Xin Chen ◽  
...  
Keyword(s):  
Catalytic Efficiency ◽  
Trna Synthetase ◽  
Modular Construction ◽  
Aquifex Aeolicus ◽  
Trna Synthetases ◽  
Naturally Occurring ◽  
Aminoacyl Trna Synthetases ◽  
Editing Domain ◽  
Editing Activity ◽  
Shed Light

aaRSs (aminoacyl-tRNA synthetases) establish the rules of the genetic code by catalysing the formation of aminoacyl-tRNA. The quality control for aminoacylation is achieved by editing activity, which is usually carried out by a discrete editing domain. For LeuRS (leucyl-tRNA synthetase), the CP1 (connective peptide 1) domain is the editing domain responsible for hydrolysing mischarged tRNA. The CP1 domain is universally present in LeuRSs, except MmLeuRS (Mycoplasma mobile LeuRS). The substitute of CP1 in MmLeuRS is a nonapeptide (MmLinker). In the present study, we show that the MmLinker, which is critical for the aminoacylation activity of MmLeuRS, could confer remarkable tRNA-charging activity on the inactive CP1-deleted LeuRS from Escherichia coli (EcLeuRS) and Aquifex aeolicus (AaLeuRS). Furthermore, CP1 from EcLeuRS could functionally compensate for the MmLinker and endow MmLeuRS with post-transfer editing capability. These investigations provide a mechanistic framework for the modular construction of aaRSs and their co-ordination to achieve catalytic efficiency and fidelity. These results also show that the pre-transfer editing function of LeuRS originates from its conserved synthetic domain and shed light on future study of the mechanism.

scholarly journals Genetic Validation of Leishmania donovani Lysyl-tRNA Synthetase Shows that It Is Indispensable for Parasite Growth and Infectivity

mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Sanya Chadha ◽  
N. Arjunreddy Mallampudi ◽  
Debendra K. Mohapatra ◽  
Rentala Madhubala
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Essential Gene ◽  
Protozoan Parasite ◽  
Protein Translation ◽  
Trna Synthetase ◽  
Parasite Growth ◽  
Coding Sequences ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases

ABSTRACT Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis. Increasing resistance and severe side effects of existing drugs have led to the need to identify new chemotherapeutic targets. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and are required for protein synthesis. aaRSs are known drug targets for bacterial and fungal pathogens. Here, we have characterized and evaluated the essentiality of L. donovani lysyl-tRNA synthetase (LdLysRS). Two different coding sequences for lysyl-tRNA synthetases are annotated in the Leishmania genome database. LdLysRS-1 (LdBPK_150270.1), located on chromosome 15, is closer to apicomplexans and eukaryotes, whereas LdLysRS-2 (LdBPK_300130.1), present on chromosome 30, is closer to bacteria. In the present study, we have characterized LdLysRS-1. Recombinant LdLysRS-1 displayed aminoacylation activity, and the protein localized to the cytosol. The LdLysRS-1 heterozygous mutants had a restrictive growth phenotype and attenuated infectivity. LdLysRS-1 appears to be an essential gene, as a chromosomal knockout of LdLysRS-1 could be generated when the gene was provided on a rescuing plasmid. Cladosporin, a fungal secondary metabolite and a known inhibitor of LysRS, was more potent against promastigotes (50% inhibitory concentration [IC50], 4.19 µM) and intracellular amastigotes (IC50, 1.09 µM) than were isomers of cladosporin (3-epi-isocladosporin and isocladosporin). These compounds exhibited low toxicity to mammalian cells. The specificity of inhibition of parasite growth caused by these inhibitors was further assessed using LdLysRS-1 heterozygous mutant strains and rescue mutant promastigotes. These inhibitors inhibited the aminoacylation activity of recombinant LdLysRS. Our data provide a framework for the development of a new class of drugs against this parasite. IMPORTANCE Aminoacyl-tRNA synthetases are housekeeping enzymes essential for protein translation, providing charged tRNAs for the proper construction of peptide chains. These enzymes provide raw materials for protein translation and also ensure fidelity of translation. L. donovani is a protozoan parasite that causes visceral leishmaniasis. It is a continuously proliferating parasite that depends heavily on efficient protein translation. Lysyl-tRNA synthetase is one of the aaRSs which charges lysine to its cognate tRNA. Two different coding sequences for lysyl-tRNA synthetases (LdLysRS) are present in this parasite. LdLysRS-1 is closer to apicomplexans and eukaryotes, whereas LdLysRS-2 is closer to bacteria. Here, we have characterized LdLysRS-1 of L. donovani. LdLysRS-1 appears to be an essential gene, as the chromosomal null mutants did not survive. The heterozygous mutants showed slower growth kinetics and exhibited attenuated virulence. This study also provides a platform to explore LdLysRS-1 as a potential drug target.

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