6.1.1.18: glutamine-tRNA ligase
This is an abbreviated version!
For detailed information about glutamine-tRNA ligase, go to the full flat file.
Word Map on EC 6.1.1.18
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6.1.1.18
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synthetases
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aminoacyl-trna
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aminoacylation
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anticodon
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glutamyl-trna
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glutaminylation
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gln-trnagln
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noncognate
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aarss
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trna-dependent
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mischarging
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transamidation
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asnrs
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aspartyl-trna
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trna2gln
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nondiscriminating
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trnatyr
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misaminoacylation
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glurss
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misacylated
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ilers
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cysrs
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anticodon-binding
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valrs
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gatcab
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gln-trna
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drug development
- 6.1.1.18
- synthetases
- aminoacyl-trna
- aminoacylation
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anticodon
- glutamyl-trna
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glutaminylation
- gln-trnagln
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noncognate
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aarss
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trna-dependent
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mischarging
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transamidation
- asnrs
- aspartyl-trna
- trna2gln
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nondiscriminating
- trnatyr
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misaminoacylation
- glurss
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misacylated
- ilers
- cysrs
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anticodon-binding
- valrs
- gatcab
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gln-trna
- drug development
Reaction
Synonyms
class I glutaminyl-tRNA synthetase, cytosolic glutaminyl-tRNA synthetase, Gln-RS, Gln4, GlnRS, Glutamine translase, Glutamine--tRNA ligase, Glutamine-tRNA synthetase, glutaminyl tRNA synthetase, Glutaminyl-transfer ribonucleate synthetase, Glutaminyl-transfer RNA synthetase, Glutaminyl-tRNA synthetase, glutaminyltRNA synthetase, glutamyl/glutaminyl-tRNA synthetase, QARS, QRS, Synthetase, glutaminyl-transfer ribonucleate, Vegetative specific protein H4
ECTree
6.1.1.18 glutamine-tRNA ligaseAdvanced search results
results (
results (Engineering
Engineering on EC 6.1.1.18 - glutamine-tRNA ligase
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PROTEIN VARIANTS 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
C229R
site-directed mutagenesis, transplanting the conserved arginine residue from glutamyl-tRNA synthetase, EC 6.1.1.17, to glutaminyltRNA synthetase improves the KM of GlnRS for noncognate glutamate
C229R/Q255I
site-directed mutagenesis, comparison of mutant activity with glutamate and glutamine to charge tRNAGln to the wild-type activity, the mutant shows no activity with L-Gln, but weakly with L-Glu
C229R/Q255I/S227A/F233Y
site-directed mutagenesis, comparison of mutant activity with glutamate and glutamine to charge tRNAGln to the wild-type activity, the mutant shows no activity with L-Gln, but activity with L-Glu
cGluGlnRS
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a chimeric protein, consisting of the catalytic domain of GluRS and the anticodon-binding domain of GlnRS, is constructed
D235A
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saturation mutagenesis, only little complementation of glnS-deficient strain
D486R/L488Q
the double mutant causes a relaxed tRNA anticodon specificity
D66E
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saturation mutagenesis, 18fold increased Km for glutamine, decreased turnover
D66F
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saturation mutagenesis, highly increased Km for glutamine, 1200fold decrease in activity
D66G
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saturation mutagenesis, only little complementation of glnS-deficient strain
D66H
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saturation mutagenesis, only little complementation of glnS-deficient strain
D66R
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saturation mutagenesis, only little complementation of glnS-deficient strain
D81Q
site-diretced mutagenesis, the mutant has and increased, inverted stereospecificity. D81Q is predicted to lead to a rotated ligand backbone and an increased, not a decreased L-Tyr preference
E222K
site-directed mutagenesis, mutational structure-function study, the residue is part of the invariant Hub, the mutation leads to mischarging and affected cognate tRNAGln recognition
E323A
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site-directed mutagenesis, the mutation produces small but consistent 2 to 3fold improvements in glutamine-binding affinity compared to the wild-type enzyme
E34A
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site-directed mutagenesis, the mutant shows highly increased Km and reduced kcat and activity compared to the wild-type enzyme
E34D
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site-directed mutagenesis, the mutant shows highly increased Km and reduced kcat and activity compared to the wild-type enzyme
E34Q
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site-directed mutagenesis, the mutant shows highly increased Km and reduced kcat and activity compared to the wild-type enzyme
E73A
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site-directed mutagenesis, the mutant shows highly increased Km and reduced kcat and activity compared to the wild-type enzyme
E73Q
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site-directed mutagenesis, the mutant shows highly increased Km and reduced kcat and activity compared to the wild-type enzyme, product release remains the rate-limiting step in E73Q
F233D
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saturation mutagenesis, highly increased Km for glutamine, 3700fold decrease in activity
F233L
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saturation mutagenesis, 19fold increased Km for glutamine, decreased turnover
F233Y
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saturation mutagenesis, increased Km for glutamine, increased turnover
F90L
K194A
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site-directed mutagenesis, the mutation perturbs the dissociation constant in ATP binding
K401A
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site-directed mutagenesis, the mutant shows reduced kcat compared to the wild-type enzyme
L136A
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site-directed mutagenesis, the mutation perturbs the dissociation constant in ATP binding
N320A
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site-directed mutagenesis, the mutation produces small but consistent 2 to 3fold improvements in glutamine-binding affinity compared to the wild-type enzyme
N336A
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site-directed mutagenesis, the mutation removes contact with the ribose at U38, but does not significantly influence glutamine affinity
N370A
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site-directed mutagenesis, the mutation removes contact with the base of U38, but does not significantly influence glutamine affinity
Q255I
site-directed mutagenesis, mutational structure-function study, the residue is part of the invariant Hub, the mutation leads to reduced specificity for cognate Gln recognition and increased Glu recognition
Q318A
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site-directed mutagenesis, the mutation produces small but consistent 2 to 3fold improvements in glutamine-binding affinity compared to the wild-type enzyme
Q517A
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site-directed mutagenesis, the mutant shows reduced kcat compared to the wild-type enzyme
R260Q
site-diretced mutagenesis, mutating Arg260 to the homologous but neutral Gln does not reduce the L-GlnAMP preference, instead, the mutation produces a change in the DELTADELTAG value that is much smaller than the wild-type free energy component
R30A
site-directed mutagenesis, comparison of mutant activity with glutamate and glutamine to charge tRNAGln to the wild-type activity, the mutant shows no activity with L-Glu
R30K
site-directed mutagenesis, comparison of mutant activity with glutamate and glutamine to charge tRNAGln to the wild-type activity, the mutant shows weak activity with L-Glu
R341A
R410A
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site-directed mutagenesis, the mutation removes contact with the base of C34, but does not significantly influence glutamine affinity
R520A
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site-directed mutagenesis, the mutant shows reduced kcat compared to the wild-type enzyme
R545A
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site-directed mutagenesis, the mutant shows reduced kcat compared to the wild-type enzyme
T316A
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site-directed mutagenesis, the mutation produces small but consistent 2 to 3fold improvements in glutamine-binding affinity compared to the wild-type enzyme
T547A
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site-directed mutagenesis, the mutant shows reduced kcat compared to the wild-type enzyme
Y211F
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saturation mutagenesis, 60fold increased Km for glutamine, decreased turnover
Y211F/F233Y
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saturation mutagenesis, increased Km for glutamine, about 6fold decreased activity
Y211G
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saturation mutagenesis, only little complementation of glnS-deficient strain
Y211H
site-directed mutagenesis, mutational structure-function study, the residue is part of the connection in the quaternary cognate-complex, the mutants shows slow solvation dynamics in the active site
Y211L
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saturation mutagenesis, unaffected Km for glutamine, decreased turnover
Y240E
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site-directed mutagenesis, active site mutant, 5fold improved glutamic acid recognition in vitro, partial complementation of an enzyme-deficient strain
Y240E/G
site-directed mutagenesis, mutational structure-function study, the residue is part of the Hub common to ligand-free and quaternary cognate-complex, the mutant shows increased Glu recognition in vitro and in vivo
Y240G
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site-directed mutagenesis, active site mutant, 3fold improved glutamic acid recognition in vitro, partial complementation of an enzyme-deficient strain
G45V
G45V/R403W
naturally occuring mutation involved in progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres, the mutant shows a highly reduced aminoacylation activity, heterozygous mutations
K496stop
naturally occuring mutation involved in early-onset epileptic encephalopathy (EOEE), heterozygous mutation leading to a deletion of part of the catalytic domain and the entire anticodon-binding domain, a loss-of-function mutant
R403W
R515W
Y57H
Y57H/R515W
occuring mutation involved in progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres, the mutant shows a highly reduced aminoacylation activity, heterozygous mutations
additional information
F90L
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site-directed mutagenesis, active site mutant, 5fold improved glutamic acid recognition in vitro, in vivo the mutant shows a 40% reduced growth rate, partial complementation of an enzyme-deficient strain
F90L
site-directed mutagenesis, mutational structure-function study, the residue is part of the connection in the active site network, the mutant shows increased Glu recognition in vitro and in vivo
R341A
site-directed mutagenesis, mutational structure-function study, the residue is part of the Hub common to all liganded complex, the mutation affects anticodon recognition
R341A
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site-directed mutagenesis, the mutation deletes a hydrogen bond made with the O4 moiety of the U35 base
R341A
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site-directed mutagenesis, the mutation removes contact with the base of U35, but does not significantly influence glutamine affinity
G45V
naturally occuring mutation involved in development of brain disorder, modestly affects the conformation of the N-terminal domain and the stability of GlnRS, the mutant shows reduced activity compared to the wild-type. Gly45 is in the solvent-flexible loop between helices alpha4 and alpha5
G45V
naturally occuring mutation involved in progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres, the mutation is located in the N-terminal domain required for QARS interaction with proteins in the multisynthetase complex and potentially with glutamine tRNA, the mutant shows an over 10fold reduction in aminoacylation activity, heterozygous mutation
R403W
inactive mutant, the mutant is bound to GroEL when recombinantly expressed in Escherichi coli suggesting that it is misfolded
R403W
naturally occuring mutation involved in progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres, the mutation renders QARS less soluble and disrupts the domain structure and overall folding of QARS, the mutant shows no aminoacylation activity in vitro, heterozygous mutation
R515W
inactive mutant, the mutant is bound to GroEL when recombinantly expressed in Escherichi coli suggesting that it is misfolded
R515W
naturally occuring mutation involved in progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres, the mutation renders QARS less soluble, the mutation disrupts QARS-RARS (arginyl-tRNA synthetase 1) interaction and disrupts the domain structure and overall folding of QARS, the mutant shows no aminoacylation activity in vitro, heterozygous mutation
Y57H
naturally occuring mutation involved in development of brain disorder, modestly affects the conformation of the N-terminal domain and the stability of GlnRS, the mutant shows reduced activity compared to the wild-type. Tyr57 is in the middle of helix alpha5
Y57H
naturally occuring mutation involved in early-onset epileptic encephalopathy (EOEE), heterozygous mutation, a loss-of-function missense mutation
Y57H
naturally occuring mutation involved in progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres, the mutation is located in the N-terminal domain required for QARS interaction with proteins in the multisynthetase complex and potentially with glutamine tRNA, the mutant shows an over 10fold reduction in aminoacylation activity, heterozygous mutation
additional information
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deletion mutants with C-terminal truncations and N-terminal truncations. A C-terminal deletion mutant exhibits sharp reduction in the specificity constant. Reduced stability of some of these mutants
additional information
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strain HAPPY101 allows plasmid-mediated expression of detrimental GlnRS mutants, which cannot complement the chromosomal glnS deletion in Escherichia coli strain X3R2
additional information
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3 misacylating mutant enzymes with reduced ability to discriminate between cognate and noncognate base pairs at position 3-70
additional information
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temperature-sensitive mutant enzyme, no change in affinity for glutamine
additional information
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construction of a truncated enzyme form, partial complementation of an enzyme-deficient strain, reduced growth rate in vivo
additional information
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construction of a chimeric glutamyl:glutaminyl-tRNA synthetase, cGluGlnRS, consisting of the catalytic domain of the GluRS and the anti-codon binding domain of the GlnRS. The chimeric mutant shows detectable glutamylation activity with Escherichia coli tRNAGlu and is capable of complementing a ts-GluRS strain at non-permissive temperatures. The GlnRS anticodon-binding domain in cGluGlnRS enhances kcat for glutamylation, interaction analysis, overview
additional information
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cumulative replacement of other primary binding site residues than Cys229 in GlnRS, with those of GluRS, only slightly improves the ability of the GlnRS active site to accommodate glutamate. Introduction of 22 amino acid replacements and one deletion, including substitution of the entire primary binding site and two surface loops adjacent to the region disrupted in C229R, improves the capacity of Escherichia coli GlnRS to synthesize misacylated Glu-tRNAGln by 16000fold. This hybrid enzyme recapitulates the function of misacylating GluRS enzymes found in organisms that synthesize Gln-tRNAGln by an alternative pathway, overview
additional information
cumulative replacement of other primary binding site residues than Cys229 in GlnRS, with those of GluRS, only slightly improves the ability of the GlnRS active site to accommodate glutamate. Introduction of 22 amino acid replacements and one deletion, including substitution of the entire primary binding site and two surface loops adjacent to the region disrupted in C229R, improves the capacity of Escherichia coli GlnRS to synthesize misacylated Glu-tRNAGln by 16000fold. This hybrid enzyme recapitulates the function of misacylating GluRS enzymes found in organisms that synthesize Gln-tRNAGln by an alternative pathway, overview
additional information
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the engineered mutant hybrid C229R Gln-RS, EC 6.1.1.18, shows activity with L-glutamine or L-glutamate and tRNAGln like the nondiscriminating enzyme, EC 6.1.1.24. Introduction of 22 amino acid replacements and one deletion, including substitution of the entire primary binding site and two surface loops adjacent to the region disrupted in the mutant C229R, improves the capacity of the mutant enzyme to synthesize misacylated Glu-tRNAGln by 16000fold, overview
additional information
the engineered mutant hybrid C229R Gln-RS, EC 6.1.1.18, shows activity with L-glutamine or L-glutamate and tRNAGln like the nondiscriminating enzyme, EC 6.1.1.24. Introduction of 22 amino acid replacements and one deletion, including substitution of the entire primary binding site and two surface loops adjacent to the region disrupted in the mutant C229R, improves the capacity of the mutant enzyme to synthesize misacylated Glu-tRNAGln by 16000fold, overview
additional information
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a deletion mutant comprising only the C-terminal catalytic domain is targeted into the multienzyme complex, while a deletion mutant comprising only the N-terminal domain is not
additional information
generation of truncated mutants DELTAN1 (116-775) with reduced activity compared to the wild-type, and DELTANTD (183-775) with no activity
additional information
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generation of truncated mutants DELTAN1 (116-775) with reduced activity compared to the wild-type, and DELTANTD (183-775) with no activity
additional information
microcephaly and neurodegeneration in two nonconsanguineous families and the identification of QARS mutations, phenotypes, overview
additional information
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truncated enzyme form lacking the NH2-terminal domain, with modest increase in Km value for glutamine and ATP and no difference in kcat for aminoacylation or Km for tRNA
additional information
construction of a C-terminal catalytic domain (QRS-C) of the QRS gene, a region corresponding to residues 255-805 of the annotated full-length gene, and of an N-terminal domain contruct
additional information
Toxoplasma gondii ATCC 50611 / Me49
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construction of a C-terminal catalytic domain (QRS-C) of the QRS gene, a region corresponding to residues 255-805 of the annotated full-length gene, and of an N-terminal domain contruct
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