6.1.1.4: leucine-tRNA ligase
This is an abbreviated version!
For detailed information about leucine-tRNA ligase, go to the full flat file.
Word Map on EC 6.1.1.4
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6.1.1.4
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aminoacyl-trna
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synthetases
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aminoacylation
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fidelity
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leucylation
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aarss
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mischarged
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post-transfer
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norvaline
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perrault
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anticodon
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aeolicus
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isoacceptors
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misactivated
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aquifex
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ilers
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noncognate
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valrs
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benzoxaborole
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isoleucyl-trna
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misaminoacylated
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hsd17b4
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kmsks
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metrs
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pour
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trnaser
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clinique
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trnaleuuur
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valyl-trna
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isoleucyl
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trna-dependent
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pre-transfer
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drug development
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medicine
- 6.1.1.4
- aminoacyl-trna
- synthetases
- aminoacylation
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fidelity
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leucylation
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aarss
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mischarged
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post-transfer
- norvaline
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perrault
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anticodon
- aeolicus
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isoacceptors
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misactivated
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aquifex
- ilers
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noncognate
- valrs
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benzoxaborole
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isoleucyl-trna
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misaminoacylated
- hsd17b4
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kmsks
- metrs
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pour
- trnaser
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clinique
- trnaleuuur
- valyl-trna
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isoleucyl
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trna-dependent
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pre-transfer
- drug development
- medicine
Reaction
Synonyms
AaLeuRS, alphabeta-LeuRS, b0642, cytoplasmic LeuRS, EcLeuRS, GlLeuRS, HcleuRS, hs mt LeuRS, JW0637, LARS, LARS1, LARS2, Leucine translase, Leucine--tRNA ligase, Leucyl-transfer ribonucleate synthetase, Leucyl-transfer ribonucleic acid synthetase, Leucyl-transfer RNA synthetase, leucyl-tRNA ligase, leucyl-tRNA syntethase, Leucyl-tRNA synthetase, leucyl-tRNA synthetase 1, leucyl—tRNA synthetase, LeuRS, LeuRS1, LeuRS2, LeuRSTT, leuS, LRS, MmLeuRS, More, mt leucyl-tRNA synthetase, mt-LeuRS, mtLeuRS, PhLeuRS, Synthetase, leucyl-transfer ribonucleate, ycLeuRS
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General Information
General Information on EC 6.1.1.4 - leucine-tRNA ligase
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evolution
malfunction
metabolism
physiological function
additional information
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the family of leucyl-tRNA synthetases is divided into prokaryotic and eukaryal/archaeal groups according to the presence and position of specific insertions and extensions. e.g. the LSD1, i.e. leucine-specific domain 1, which is naturally present in eukaryal/archaeal LeuRSs, but absent from prokaryotic LeuRSs. The LSD1s from organisms of both groups are dispensable for post-transfer editing
evolution
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the family of leucyl-tRNA synthetases is divided into prokaryotic and eukaryal/archaeal groups according to the presence and position of specific insertions and extensions. e.g. the LSD1, i.e. leucine-specific domain 1, which is naturally present in eukaryal/archaeal LeuRSs, but absent from prokaryotic LeuRSs. The LSD1s from organisms of both groups are dispensable for post-transfer editing
evolution
based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-binding fold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Sequence comparisons of the stem contact-fold domain (SC-fold) involved in editing, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
evolution
based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-binding fold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Sequence comparisons of the stem contact-fold domain (SC-fold) involved in editing, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
evolution
Mesomycoplasma mobile
based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-bindingfold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Although post-transfer editing is carried out by the CP1 domain in most LeuRSs, this domain has been naturally deleted in LeuRS from Mycoplasma mobile (MmLeuRS). Sequence comparisons of the stem contact-fold domain (SC-fold) involved in editing, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
evolution
based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-bindingfold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Sequence comparison of the EcLeuRS stem contact-fold domain (SC-fold) with editing-deficient enzymes suggests that key residues of this module have evolved an adaptive strategy to follow the editing functions of LeuRS, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
evolution
based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-bindingfold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Sequence comparisons of the stem contact-fold domain (SC-fold) involved in editing, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
evolution
enzyme leucyl-tRNA synthetase is part of the aminoacyl-tRNA synthetase (aaRS) family
evolution
leucyl-tRNA synthetase (LeuRS) belongs to class Ia aminoacyl-tRNA synthetases (AaRSs). Based on their similar structures, LeuRS, IleRS, and ValRS are collectively known as LIVRS, all of which contain a representative catalytic core consisting of a Rossmann fold. Besides the conservative Rossmann fold, almost all LeuRSs contain a large insertion domain called connective peptide 1 (CP1) within the sequence of the catalytic core. CP1 folds independently in the tertiary structure and is defined as a classic editing domain, in which the aminoacyl bond of mischarged aatRNA is hydrolyzed (post-transfer editing) to ensure the fidelity of the catalytic process
evolution
Mesomycoplasma mobile ATCC 43663 / 163K / NCTC 11711
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based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-bindingfold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Although post-transfer editing is carried out by the CP1 domain in most LeuRSs, this domain has been naturally deleted in LeuRS from Mycoplasma mobile (MmLeuRS). Sequence comparisons of the stem contact-fold domain (SC-fold) involved in editing, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
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evolution
Pyrococcus horikoshii ATCC 700860 / DSM 12428 / JCM 9974 / NBRC 100139 / OT-3
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based on sequence homology and the structures of the catalytic active sites, aaRSs are divided into two classes of 10 members each. Class I synthetases are further divided into three subclasses, a, b, and c, according to sequence homology. Leucyl-tRNA synthetase (LeuRS) belongs to class I aaRSs that include a typical Rossmann dinucleotide-bindingfold active site architecture with the signature sequence modules HIGH and KMSKS. According to evolutionary models, the primitive catalytic core is extended by the insertion and/or fusion of additional domains (also called modules) in LeuRSs, most of which have inserted a large connective polypeptide 1 (CP1) domain that is responsible for amino acid editing. To ensure translation accuracy, LeuRSs have evolved a mechanism to remove aminoacyl AMP (aa-AMP, pre-transfer editing) and aa-tRNA (post-transfer editing). Sequence comparisons of the stem contact-fold domain (SC-fold) involved in editing, basic residues on helix alpha3 of the SC-fold are critical for catalytic efficiency, overview
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replacement of Giardia lamblia eukarya-specific insertion 1, GlESI, by human eukarya-specific insertion 1, HsESI, impairs leucine activation, aminoacylation and post-transfer editing functions without changing the editing specificity
malfunction
abrogation of the LeuRS specificity determinant threonine 252 does not improve the affinity of the editing site for the cognate leucine as expected, but instead substantially enhances the rate of leucyl-tRNALeu hydrolysis. Molecular dynamics simulations reveals that the wild-type enzyme, but not the T252A mutant, enforces leucine to adopt the side-chain conformation that promotes the steric exclusion of a putative catalytic water
malfunction
knockdown of LRS in HEK-293 cells results in impaired leucine-stimulated S6K1 phosphorylation, total amino acid stimulation of pS6K1 is also significantly reduced. Knockdown of LRS decreasesVps34 activity induced by leucine or total amino acids. Knockdown of LRS does not affect the protein levels of mTOR, raptor, Vps34, and Rag GTPases
malfunction
Lars knockdown does not decrease phosphorylated mTOR in differentiated myotubes, nor does it affect the hypertrophy of myotubes. Extracellular flux analysis shows that Lars knockdown does not affect the metabolism (glycolysis and mitochondrial respiration) of myotubes
malfunction
mutation of highly conserved basic residues on the third alpha-helix of the KMSKS catalytic loop domain impairs the affinity of LeuRS for the anticodon stem of tRNALeu, which decreases both aminoacylation and editing activities
malfunction
mutations in mitochondrial DNA determine important human diseases. The majority of the known pathogenic mutations are located in transfer RNA (tRNA) genes and are responsible for a wide range of currently untreatable disorders. The detrimental effects of mt-tRNA point mutations can be attenuated by increasing the expression of the cognate mt-aminoacyl-tRNA synthetases (aaRSs). The isolated C-terminal domain of human mt-leucyl-tRNA synthetase (LeuRS-Cterm) localizes to mitochondria and ameliorates the energetic defect in trans-mitochondrial cybrids carrying mutations either in the cognate mt-tRNALeu(UUR) or in the non-cognate mt-tRNAIle gene.Since the mt-LeuRS-Cterm does not possess catalytic activity, its rescuing ability is most likely mediated by a chaperon-like effect, consisting in the stabilization of the tRNA structure altered by the mutation
malfunction
siRNA-mediated knockdown of LeuRS leads to suppression of rapamycin (mTOR), p-mTOR, ribosomal protein S6 kinase 1 (S6K1), p-S6K1, beta-casein, sterol regulatory element binding-protein 1c (SREBP-1c), glucose transporter 1 (GLUT1), and cyclin D1 mRNA and protein expression. LeuRS knockdown reduces cell growth, the expression of lactation-associated proteins, and milk synthesis
malfunction
the C-terminal domain of human mt leucyl-tRNA synthetase is both necessary and sufficient to improve the pathologic phenotype associated either with these mild mutations or with the severe m.3243A>G mutation in the mt-tRNALeu(UUR) gene, overview. The small, non-catalytic domain is able to directly and specifically interact in vitro with human mt-tRNALeu(UUR) with high affinity and stability and, with lower affinity, with mt-tRNAIle. The carboxyterminal domain of human mt leucyl-tRNA synthetase can be used to correct mt dysfunctions caused by mt-tRNA mutations. The Cterm domain of human mt-LeuRS directly interacts with mt-tRNALeu(UUR) and mt-tRNAIle in vitro
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isoform LeuRS1 generates Leu-tRNALeu for protein biosynthesis and exhibits obvious post-transfer editing activity to prevent generation of mischarged tRNALeu
metabolism
LRS-RagD interaction plays a pivotal role in the nutrientdependent mTORC1 signalling pathway
metabolism
mTORC1 lysosomal translocation and activation in response to amino acids requires the GTP-bound form of RagA or B as well as the GDP-bound form of RagC or D. The Ragulator complex and the GATOR1 complex act as GEF (guanine nucleotide exchange factor) and GAP (GTPase activating protein) for RagA/B, respectively. Role of LRS as a leucine sensor upstream of TORC1. Two other tRNA synthetases, IRS (isoleucyl-tRNA synthetase) and EPRS (glutamyl-prolyl-tRNA synthetase), are both in the multi-tRNA synthetase complex together with enzyme LRS, but both have no effect on leucine-stimulated Vps34 activity. LRS directly regulates Vps34 activity
metabolism
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isoform LeuRS1 generates Leu-tRNALeu for protein biosynthesis and exhibits obvious post-transfer editing activity to prevent generation of mischarged tRNALeu
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existence of a tRNA-independent pretransfer editing pathway in leucyltRNA synthetases from Aquifex aeolicus. This editing pathway is distinct from the post-transfer editing site and may occur at the synthetic catalytic site
physiological function
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leucyl-tRNA synthetase is an essential RNA splicing factor for yeast mitochondrial introns. RNA deletion mutants of the large bI4 intron are active in RNA splicing and the activity of the minimized bI4 intron is enhanced in vitro by the presence of the bI4 maturase or LeuRS
physiological function
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the A3243G mutation of the tRNALeu gene causes mitochondrial encephalomyopathy, lactic acidosis, and stroke-like symptoms and 2% of cases of type 2 diabetes. The alteration of aminoacylation of tRNALeu(UUR) caused by the A3243G mutation leads to mitochondrial translational defects and thereby reduces the aminoacylating efficiencies of tRNALeu(UUR) as well as of tRNAAla and tRNAMet
physiological function
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aminoacyl-tRNA synthetases are critical for the translational process, catalyzing the attachment of specific amino acids to their cognate tRNAs. To ensure formation of the correct aminoacyl-tRNA, and thereby enhance the reliability of translation, several aminoacyl-tRNA synthetases have an editing capability that hinders formation of misaminoacylated tRNAs, analysis of the mechanism of the editing reaction for class I enzyme leucyl-tRNA synthetase complexed with a misaminoacylated tRNALeu by initio hybrid quantum mechanical/molecular mechanical potentials in conjunction with molecular dynamics simulations, overview. Editing is a self-cleavage reaction of the tRNA and so it is the tRNA, and not the protein, that drives the reaction. The protein does, however, have an important stabilizing effect on some high-energy intermediates along the reaction path, which is more efficient than the ribozyme would be alone. This indicates that editing is achieved by a hybrid ribozyme/protein catalyst. The water molecule that acts as the nucleophile in the editing reaction is activated by a 3'-hydroxyl group at the 3'-end of tRNALeu and that the O2' atom of the leaving group of the substrate is capped by one of the water's hydrogen atoms
physiological function
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aminoacyl-tRNA synthetases have evolved editing mechanisms to hydrolyze misactivated amino acids (pre-transfer editing) or misacylated tRNAs (post-transfer editing). Class Ia leucyl-tRNA synthetase may misactivate various natural and non-protein amino acids and then mischarge tRNALeu. The fidelity of prokaryotic LeuRS depends on multiple editing pathways to clear the incorrect intermediates and products in every step of aminoacylation reaction. Post-transfer editing as a final checkpoint of the reaction is very important to prevent mis-incorporation in vitro
physiological function
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the carboxy-terminal domain of human mitochondrial leucyl-tRNA synthetase can be used to correct mitochondrial dysfunctions caused by mitochondrial tRNA mutations like the phenotype of m.3243A>G MTTL1 mutant cybrids
physiological function
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the enzyme is a leucine sensor for serine/threonine kinase TORC1 and interacts with Gtr1
physiological function
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the enzyme is a leucine sensor for serine/threonine kinase TORC1 and interacts with Gtr2
physiological function
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the enzyme naturally produces mischarged tRNALeu
physiological function
Mesomycoplasma mobile
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the enzyme naturally produces mischarged tRNALeu
physiological function
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the enzyme plays a critical role in amino acid-induced mammalian target of rapamycin C1 activation by sensing intracellular leucine concentration and initiating molecular events leading to mammalian target of rapamycin C1 activation. The enzyme directly binds to Rag GTPase, the mediator of amino acid signaling to mTORC1, in an amino acid-dependent manner and functions as a GTPase-activating protein for Rag GTPase to activate mammalian target of rapamycin C1
physiological function
aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
physiological function
aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
physiological function
Mesomycoplasma mobile
aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
physiological function
aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
physiological function
aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
physiological function
Escherichia coli leucyl-tRNA synthetase (LeuRS) is an essential multi-domain metalloenzyme that aminoacylates tRNALeu with leucine. Enzyme LeuRS is an essential enzyme that relies on specialized domains to facilitate the aminoacylation reaction. Structural changes within the ZN-1 domain play a central role in LeuRS's catalytic cycle. The enzyme performs a Zn2+ dependent translocation mechanism for charged tRNALeu, Zn2+ is an architectural cornerstone of the ZN-1 domain and that without its geometric coordination the domain collapses. Residues C159, C176 and C179 coordinate Zn2+ and that this interaction is essential for leucylation to occur, but is not essential for deacylation
physiological function
leucyl-tRNA synthetase (Lars) is an intracellular sensor of leucine involved in the activation of mTOR signaling with a physiological role in skeletal muscle cells, potential roles of Lars for the activation of mTOR signaling, skeletal muscle cell differentiation, hypertrophy, and metabolism. Enzyme Lars directly binds to Rag GTPase, a known mediator of amino acid signaling to mTORC1, in a leucine-dependent manner and acts as a GTPase-activating protein for Rag GTPase to activate mTOR signaling. Lars is required for skeletal muscle differentiation through the activation of mTOR signaling, but not for hypertrophy or metabolic alteration of myotubes, link between Lars and mTOR activation in muscle cells and the physiological role of myoblast differentiation. Lars is essential for the activation of mTOR signaling in skeletal muscle cells and myogenic differentiation thought the induction of Igf2 expression
physiological function
leucyl-tRNA synthetase (LRS) is a leucine sensor for the activation of Vps34-PLD1 upstream of mTORC1. LRS binds to RagD-GTP, and forms a LRS-RagD complex, which translocates mTORC1 from the cytosol to the lysosome surface for subsequent activation of the mTORC1 signalling pathway. LRS is necessary for amino acid-induced Vps34 activation, cellular phosphatidylinositol-3-phosphate level increase, PLD1 activation, and PLD1 lysosomal translocation. Leucine binding but not tRNA charging activity of LRS is required for this regulation. LRS directly interacts with Vps34 in a non-autophagic complex, and activates Vps34 kinase activity in a leucine-dependent manner. Vps34 and PLD1 are required to mediate LRS activation of mTORC1. Only non-autophagic Vps34 complexes are involved in amino acid signaling to mTOR. LRS is necessary for amino acid activation of PLD1. Overexpression of LRS enhanced amino acid activation of S6K1
physiological function
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leucyl-tRNA synthetase (LRS) plays major roles in providing leucine-tRNA and activating mechanistic target of rapamycin complex 1 (mTORC1) through intracellular leucine sensing. mTORC1 activated by amino acids affects the influence on physiology functions including cell proliferation, protein synthesis and autophagy in various organisms. Crosstalk between leucine sensing, LRS translocation, RagD interaction, and mTORC1 activation, mTORC1 activation is related to LRS translocation dependent on leucine, analysis of relationship between mTORC1 activation and LRS translocation, overview
physiological function
leucyl-tRNA synthetase regulates lactation and cell proliferation via mTOR signaling in dairy cow mammary epithelial cells, role of LeuRS as an intracellular L-leucine sensor for the mTORC1 pathway. LeuRS up-regulates the mTOR pathway to promote proliferation and lactation of dairy cow mammary epithelial cells (DCMECs) in response to changes in the intracellular leucine concentration. Treatment with L-leucine increases DCMECs viability and proliferation, as well as mammalian target of rapamycin (mTOR), p-mTOR, ribosomal protein S6 kinase 1 (S6K1), p-S6K1, beta-casein, sterol regulatory element binding-protein 1c (SREBP-1c), glucose transporter 1 (GLUT1), and cyclin D1 mRNA and protein expression via activity of enzyme LeuRS. Secretion of lactose and triglyceride are also increased. Effect of leucine on LeuRS to regulate cell growth and expression of proteins involved in mTOR signaling in DCMECs
physiological function
leucyl-tRNA synthetases (LeuRSs) catalyze the linkage of leucine with tRNALeu
physiological function
the direct interaction between enzyme LRS and RagD activates mTORC1 in live cells under leucine-deprived conditions. The nutrient sensing mechanism of mTORC1, particularly for Leu, an essential biomarker for nutrient status in cellular systems, is regulated by protein-protein interactions between LRS and RagD and directly mediate mTORC1 activation
physiological function
the ligation of amino acid to tRNA for purposes of protein synthesis proceeds in two steps, bothcatalyzed by a corresponding aminoacyl-tRNA synthetase(aaRS). The amino acid is first activated to anaminoacyl-adenylate (aa-AMP) intermediate at theexpense of ATP, followed by the transfer of aminoacylmoiety to the 2'- or 3'-OH groups at the terminal ribose of the cognate tRNA. Both steps occurwithin the same synthetic/aminoacylation active site located in thecatalytic aaRS domain. Based on the topology of the catalytic domains, the conserved recognition peptides and interaction with the tRNA, aaRSs can be divided into two classes, I and II. The mechanisms of aminoacylation and editing are basically conserved among the classes, although some class-specific features have been recognized. Editing aaRSs exercise specificity through a double-selection mechanism that uses structural/chemical differences between the cognate and non-cognate amino acids twice but in different ways. Leu-tRNALeu is excluded from proofreading basically at the level of catalysis, not binding. This is accomplished by the side chain of the cognate leucine, which adopts a conformation that sterically precludes the positioning of a water nucleophile near the tRNA-assisted hydrolytic machinery. The A76 3'-OH group is a crucial residue in the positioning and activation of the catalytic water. Deacylation mechanism of the enzyme, simulation and modeling, overview
physiological function
Mesomycoplasma mobile ATCC 43663 / 163K / NCTC 11711
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aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
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physiological function
Pyrococcus horikoshii ATCC 700860 / DSM 12428 / JCM 9974 / NBRC 100139 / OT-3
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aminoacyl-tRNA synthetases (aaRSs) are a large and diverse family of enzymes that catalyze the attachment of amino acids to their cognate tRNAs in a two-step aminoacylation reaction as follows: 1. amino acid activation by ATP hydrolysis to form an aminoacyl-adenylate intermediate, and 2. transfer of the aminoacyl moiety from the intermediate to the cognate tRNA isoacceptor to form aminoacyl-tRNA (aa-tRNA)
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activating role of C-terminal domain in the reactions of aminoacylation and editing, and its contribution to interaction with tRNALeu, overview. The C-terminal domain does is not critical for the manifestation of specificity of the enzyme of homologous RNAs, but is required for to enhance the rate of catalysis in aminoacylation and editing reaction
additional information
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human leucyl-tRNA synthetase and mitochondrial protein elongation factor EF-Tu show suppressing cross-activity on different tRNA mutants in humans and Saccharomyces cerevisiae, mechanism and specificity of suppression, overview. Suppressive activities of wild-type and mutant enzymes, overview
additional information
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leucine-specific domain 1, LSD1, is dispensable for post-transfer editing
additional information
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leucine-specific domain 1, LSD1, is dispensable for post-transfer editing
additional information
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the CP1, i.e. connective peptide 1, domain of LeuRS contains the editing active site ESI, eukarya-specific insertion 1, Thr341 serves as a specificity discriminator. Arg338 is crucial for tRNALeu charging and the Asp440 is crucial for leucine activation and aminoacylation. The post-transfer editing required the C-terminal domain, Arg338 and Asp440 of GlLeuRS
additional information
analysis of the bacterial LeuRS structures (PDB IDs 2BTE and 4AS1) reveals that the isolated C-terminal domain of human mt-leucyl-tRNA synthetase (LeuRS-Cterm) interacts with the elbow region of the cognate tRNA and establishes a higher number of contacts with the sugar-phosphate backbone than with nucleotide-specific chemical groups, preferred interaction of human mt-LeuRS-Cterm with ribose and phosphate oxygen atoms
additional information
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analysis of the bacterial LeuRS structures (PDB IDs 2BTE and 4AS1) reveals that the isolated C-terminal domain of human mt-leucyl-tRNA synthetase (LeuRS-Cterm) interacts with the elbow region of the cognate tRNA and establishes a higher number of contacts with the sugar-phosphate backbone than with nucleotide-specific chemical groups, preferred interaction of human mt-LeuRS-Cterm with ribose and phosphate oxygen atoms
additional information
enzyme structure homology modeling using the structure of Thermus thermophilus LeuRS, PDB ID 2V0C, as template
additional information
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enzyme structure homology modeling using the structure of Thermus thermophilus LeuRS, PDB ID 2V0C, as template
additional information
in silico models of the wild-type and mutated LeuRS CP1 editing domain bound to the analogues with an ester linkage between the amino acid and adenosine as in real substrates [2'-L-leucyladenosine (Leu2A) and 2?-L-norvalyladenosine (Nva2A)] are constructed based on the structure of T252A LeuRS in a complex with tRNALeu and leucyl-adenylate sulphamoyl analogue (Leu-AMS), both positioned in the synthetic active site, and Leu2AA located in the editing domain. The tRNA body dominates the binding energetics of aa-tRNA:LeuRS complex formation
additional information
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in silico models of the wild-type and mutated LeuRS CP1 editing domain bound to the analogues with an ester linkage between the amino acid and adenosine as in real substrates [2'-L-leucyladenosine (Leu2A) and 2?-L-norvalyladenosine (Nva2A)] are constructed based on the structure of T252A LeuRS in a complex with tRNALeu and leucyl-adenylate sulphamoyl analogue (Leu-AMS), both positioned in the synthetic active site, and Leu2AA located in the editing domain. The tRNA body dominates the binding energetics of aa-tRNA:LeuRS complex formation
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small-molecule protein-protein interactions modulators between LRS and RagD can be used as powerful research tools for studying the nutrient-dependent activation of mTORC1 and the subsequent biological outcome
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the CP1 hairpin editing structure, residue R236 to G256, and the flexibility of small residues and the charge of polar residues in the CP1 hairpin are crucial for the function of LeuRS. The CP1 hairpin domain is crucial for activities of leucine, leucylation of tRNALeu, and tRNA binding of hcLeuRS
additional information
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the CP1 hairpin editing structure, residue R236 to G256, and the flexibility of small residues and the charge of polar residues in the CP1 hairpin are crucial for the function of LeuRS. The CP1 hairpin domain is crucial for activities of leucine, leucylation of tRNALeu, and tRNA binding of hcLeuRS
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the KMSKS catalytic loop exhibits alpha-alpha-beta-alpha topology in class Ia and Ib aminoacyl-tRNA synthetases, two glycine residues on the third alpha-helix contribute to flexibility, leucine activation, and editing of LeuRS from Escherichia coli (EcLeuRS), acidic residues on the beta-strand enhance the editing activity of EcLeuRS and sense the size of the tRNALeu D-loop. Incorporation of acidic residues on the beta-strand stimulates the tRNA-dependent editing activity of the chimeric minimalist enzyme Mycoplasma mobile LeuRS fused to the connective polypeptide 1 editing domain and leucine-specific domain from EcLeuRS. Sequence comparison of the EcLeuRS stem contact-fold domain with editing-deficient enzymes suggests that key residues of this module have evolved an adaptive strategy to follow the editing functions of LeuRS. Amino acid residues Arg668 or Arg672 are not involved in the amino acid activation step but rather the second tRNA transfer step
additional information
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the KMSKS catalytic loop exhibits alpha-alpha-beta-alpha topology in class Ia and Ib aminoacyl-tRNA synthetases, two glycine residues on the third alpha-helix contribute to flexibility, leucine activation, and editing of LeuRS from Escherichia coli (EcLeuRS), acidic residues on the beta-strand enhance the editing activity of EcLeuRS and sense the size of the tRNALeu D-loop. Incorporation of acidic residues on the beta-strand stimulates the tRNA-dependent editing activity of the chimeric minimalist enzyme Mycoplasma mobile LeuRS fused to the connective polypeptide 1 editing domain and leucine-specific domain from EcLeuRS. Sequence comparison of the EcLeuRS stem contact-fold domain with editing-deficient enzymes suggests that key residues of this module have evolved an adaptive strategy to follow the editing functions of LeuRS. Amino acid residues Arg668 or Arg672 are not involved in the amino acid activation step but rather the second tRNA transfer step
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Mesomycoplasma mobile
the KMSKS catalytic loop exhibits alpha-alpha-beta-alpha topology in class Ia and Ib aminoacyl-tRNA synthetases. Incorporation of acidic residues on the beta-strand stimulates the tRNA-dependent editing activity of the chimeric minimalist enzyme Mycoplasma mobile LeuRS fused to the connective polypeptide 1 editing domain and leucine-specific domain from EcLeuRS, acidic residues on the beta-strand enhance the editing activity of EcLeuRS and sense the size of the tRNALeu D-loop
additional information
there are two catalytic sites, the leucylation site housed within the aminoacylation domain and the hydrolytic deacylation site housed within the CP1 editing domain, the ZN-1 domain is known to play an essential structural role in stabilizing the Leu-Amp adenylate. Structural analysis of LeuRS enzymes using Fourier transform infrared spectroscopy (FTIR), and homology modeling of LeuRS in the editing conformation, visualizing the ZN-1 domain, by using the structure in editing conformation of the LeuRS enzyme from Thermus thermophilus, PDB ID 1OBH as template, overview
additional information
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there are two catalytic sites, the leucylation site housed within the aminoacylation domain and the hydrolytic deacylation site housed within the CP1 editing domain, the ZN-1 domain is known to play an essential structural role in stabilizing the Leu-Amp adenylate. Structural analysis of LeuRS enzymes using Fourier transform infrared spectroscopy (FTIR), and homology modeling of LeuRS in the editing conformation, visualizing the ZN-1 domain, by using the structure in editing conformation of the LeuRS enzyme from Thermus thermophilus, PDB ID 1OBH as template, overview
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three human mitochondrial aminoacyl-tRNA syntethases, namely leucyl-, valyl-, and isoleucyl-tRNA synthetase are able to improve both viability and bioenergetic proficiency of human transmitochondrial cybrid cells carrying pathogenic mutations in the mt-tRNAIle gene
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three human mitochondrial aminoacyl-tRNA syntethases, namely leucyl-, valyl-, and isoleucyl-tRNA synthetase are able to improve both viability and bioenergetic proficiency of human transmitochondrial cybrid cells carrying pathogenic mutations in the mt-tRNAIle gene
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Mesomycoplasma mobile ATCC 43663 / 163K / NCTC 11711
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the KMSKS catalytic loop exhibits alpha-alpha-beta-alpha topology in class Ia and Ib aminoacyl-tRNA synthetases. Incorporation of acidic residues on the beta-strand stimulates the tRNA-dependent editing activity of the chimeric minimalist enzyme Mycoplasma mobile LeuRS fused to the connective polypeptide 1 editing domain and leucine-specific domain from EcLeuRS, acidic residues on the beta-strand enhance the editing activity of EcLeuRS and sense the size of the tRNALeu D-loop
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additional information
Mycobacterium tuberculosis ATCC 25618 / H37Rv
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enzyme structure homology modeling using the structure of Thermus thermophilus LeuRS, PDB ID 2V0C, as template
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