Cloned (Comment) | Organism |
---|---|
gene MST1, recombinant expression in Escherichia coli strain BL21(DE3) | Saccharomyces cerevisiae |
Protein Variants | Comment | Organism |
---|---|---|
additional information | a minimalist mitochondrial threonyl-tRNA synthetase exhibits tRNA-isoacceptor specificity during proofreading, complementation of a ScmtThrRS gene knockout strain. Construction of the gene encoding the chimeric Saccharomyces cerevisiae cytoplasmic-mitochondrial ThrRS (CmThrRS), overview. Role of the tRNAThr1 anticodon in editing by CmThrRS. The MST1 gene knockout strain, ScDELTAMST1, reveals that aminoacylation and tRNA binding domains co-evolved to acquire tRNAThr1 recognition capability | Saccharomyces cerevisiae |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | aminoacylation kinetics of ScmtThrRS for various tRNAThr1 mutants derived from U33a or G36, overview. Rate constants of AMP formation by chimeric mutant enzyme CmThrRS | Saccharomyces cerevisiae | |
0.00045 | - |
tRNAThr1 | pH 8.5, 30°C, recombinant enzyme | Saccharomyces cerevisiae |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrion | - |
Saccharomyces cerevisiae | 5739 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Saccharomyces cerevisiae |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + L-threonine + tRNAThr1 | Saccharomyces cerevisiae | - |
AMP + diphosphate + L-threonyl-tRNAThr1 | - |
? | |
ATP + L-threonine + tRNAThr1 | Saccharomyces cerevisiae ATCC 204508 / S288c | - |
AMP + diphosphate + L-threonyl-tRNAThr1 | - |
? | |
ATP + L-threonine + tRNAThr2 | Saccharomyces cerevisiae | - |
AMP + diphosphate + L-threonyl-tRNAThr2 | - |
? | |
ATP + L-threonine + tRNAThr2 | Saccharomyces cerevisiae ATCC 204508 / S288c | - |
AMP + diphosphate + L-threonyl-tRNAThr2 | - |
? | |
additional information | Saccharomyces cerevisiae | ScmtThrRS exhibits a tRNA-dependent pre-transfer editing activity that is specific for the tRNAThr2 isoacceptor, whereas tRNAThr1 is unable to stimulate such activity. Editing capability of tRNAThr1 with requirement for the presence of an editing domain | ? | - |
? | |
additional information | Saccharomyces cerevisiae ATCC 204508 / S288c | ScmtThrRS exhibits a tRNA-dependent pre-transfer editing activity that is specific for the tRNAThr2 isoacceptor, whereas tRNAThr1 is unable to stimulate such activity. Editing capability of tRNAThr1 with requirement for the presence of an editing domain | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Saccharomyces cerevisiae | P07236 | - |
- |
Saccharomyces cerevisiae ATCC 204508 / S288c | P07236 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + L-threonine + tRNAThr1 | - |
Saccharomyces cerevisiae | AMP + diphosphate + L-threonyl-tRNAThr1 | - |
? | |
ATP + L-threonine + tRNAThr1 | specific binding mode of mitochondrial tRNAThr1 to mitochondrial ScmtThrRS | Saccharomyces cerevisiae | AMP + diphosphate + L-threonyl-tRNAThr1 | - |
? | |
ATP + L-threonine + tRNAThr1 | - |
Saccharomyces cerevisiae ATCC 204508 / S288c | AMP + diphosphate + L-threonyl-tRNAThr1 | - |
? | |
ATP + L-threonine + tRNAThr1 | specific binding mode of mitochondrial tRNAThr1 to mitochondrial ScmtThrRS | Saccharomyces cerevisiae ATCC 204508 / S288c | AMP + diphosphate + L-threonyl-tRNAThr1 | - |
? | |
ATP + L-threonine + tRNAThr2 | - |
Saccharomyces cerevisiae | AMP + diphosphate + L-threonyl-tRNAThr2 | - |
? | |
ATP + L-threonine + tRNAThr2 | - |
Saccharomyces cerevisiae ATCC 204508 / S288c | AMP + diphosphate + L-threonyl-tRNAThr2 | - |
? | |
additional information | ScmtThrRS exhibits a tRNA-dependent pre-transfer editing activity that is specific for the tRNAThr2 isoacceptor, whereas tRNAThr1 is unable to stimulate such activity. Editing capability of tRNAThr1 with requirement for the presence of an editing domain | Saccharomyces cerevisiae | ? | - |
? | |
additional information | the enzyme, mitochondrial ThrRS (ScmtThrRS), catalyzes the aminoacylation of tRNAThr1 and tRNAThr2, U33a and G36 of tRNAThr1 are critical nucleotides for aminoacylation by ScmtThrRS. tRNAThr1 stimulates pre-transfer editing in the presence of an editing domain | Saccharomyces cerevisiae | ? | - |
? | |
additional information | ScmtThrRS exhibits a tRNA-dependent pre-transfer editing activity that is specific for the tRNAThr2 isoacceptor, whereas tRNAThr1 is unable to stimulate such activity. Editing capability of tRNAThr1 with requirement for the presence of an editing domain | Saccharomyces cerevisiae ATCC 204508 / S288c | ? | - |
? | |
additional information | the enzyme, mitochondrial ThrRS (ScmtThrRS), catalyzes the aminoacylation of tRNAThr1 and tRNAThr2, U33a and G36 of tRNAThr1 are critical nucleotides for aminoacylation by ScmtThrRS. tRNAThr1 stimulates pre-transfer editing in the presence of an editing domain | Saccharomyces cerevisiae ATCC 204508 / S288c | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | mitochondrial ThrRS (ScmtThrRS), encoded by the MST1 gene, is devoid of an editing domain, and consists only of the aminoacylation catalytic core connected to the C-terminal tRNA binding domain (CTD). Domain organization of the enzyme, overview | Saccharomyces cerevisiae |
Synonyms | Comment | Organism |
---|---|---|
Mst1 | - |
Saccharomyces cerevisiae |
ScmtThrRS | - |
Saccharomyces cerevisiae |
Threonyl-tRNA synthetase | - |
Saccharomyces cerevisiae |
ThrRS | - |
Saccharomyces cerevisiae |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Saccharomyces cerevisiae |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0338 | - |
tRNAThr1 | pH 8.5, 30°C, recombinant enzyme | Saccharomyces cerevisiae |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8.5 | - |
assay at | Saccharomyces cerevisiae |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ATP | - |
Saccharomyces cerevisiae |
General Information | Comment | Organism |
---|---|---|
evolution | the catalytic core and tRNA binding domain of ScmtThrRS co-evolved to recognize the unusual tRNAThr1. Loss of the editing domain occurred at a very early stage in the evolution of yeast, while mitochondrial tRNALeu(CUN) reassignment was a more recent event. The 34UAG36 anticodon is harbored by mitochondrial tRNALeu(CUN) in other organisms, such as humans and even the yeasts Schizosaccharomyces pombe, Candida albicans. tRNALeu(CUN) has been consistently lost in the Saccharomyces cerevisiae mitochondrion during the evolution of the 24 mitochondrial tRNA genes. tRNAThr1 is not derived from the lost tRNALeu (CUN) but from tRNAHis with a 34GUG36 anticodon | Saccharomyces cerevisiae |
additional information | the enzyme catalyzing the aminoacylation of tRNAThr1 and tRNAThr2, mitochondrial ThrRS (ScmtThrRS), encoded by the MST1 gene, is devoid of an editing domain, and consists only of the aminoacylation catalytic core connected to the C-terminal tRNA binding domain (CTD) | Saccharomyces cerevisiae |
physiological function | despite the absence of the editing domain, Saccharomyces cerevisiae mitochondrial ThrRS (ScmtThrRS) harbors a tRNA-dependent pretransfer editing activity. Only the usual tRNAThr2 stimulates pre-transfer editing, establishing the an example of a synthetase exhibiting tRNA-isoacceptor specificity during pre-transfer editing. The failure of tRNAThr1 to stimulate tRNA-dependent pre-transfer editing is due to the lack of an editing domain. tRNA-dependent pretransfer editing takes place in the aminoacylation catalytic core, tRNA-dependent editing process mechanism, overview. The anticodon nucleotides of SctRNAThr or tRNAThr2 are critical for the pre-transfer editing activity of SccytThrRS or ScmtThrRS | Saccharomyces cerevisiae |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
75.19 | - |
tRNAThr1 | pH 8.5, 30°C, recombinant enzyme | Saccharomyces cerevisiae |