Activating Compound | Comment | Organism | Structure |
---|---|---|---|
protein GSAM | stimulation of GluTR by glutamate semialdehyde 1-2 aminomutase, GSAM. GluTR activity is stimulated upon formation ofa complex with protein GSAM. This effect is observed only when GluTR contained a heme/protein ratio of 1/12. GluTR activity and the stimulation of this enzyme by protein GSAM are reduced by treatment with H2O2 | Acidithiobacillus ferrooxidans |
Cloned (Comment) | Organism |
---|---|
recombinant overexpression of His6-tagged enzyme in Escherichia coli strain BL21(DE3) | Acidithiobacillus ferrooxidans |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
H2O2 | inactivates the enzyme. H2O2 decreases the stimulation of GluTR by glutamate semialdehyde 1-2 aminomutase, GSAM | Acidithiobacillus ferrooxidans | |
heme | feedback inhibition | Acidithiobacillus ferrooxidans |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Acidithiobacillus ferrooxidans |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamyl-tRNAGlu + NADPH + H+ | Acidithiobacillus ferrooxidans | - |
L-glutamate 1-semialdehyde + NADP+ + tRNAGlu | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Acidithiobacillus ferrooxidans | B7J8J0 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography | Acidithiobacillus ferrooxidans |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamyl-tRNAGlu + NADPH + H+ | - |
Acidithiobacillus ferrooxidans | L-glutamate 1-semialdehyde + NADP+ + tRNAGlu | - |
? |
Synonyms | Comment | Organism |
---|---|---|
GluTR | - |
Acidithiobacillus ferrooxidans |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Acidithiobacillus ferrooxidans |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.2 | - |
assay at | Acidithiobacillus ferrooxidans |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | enzyme preparations with one molecule of heme bound per four GluTR subunits (heme/protein ratio of 1/4) have an increased inactivation rate by H2O2 compared to enzymes with one heme per twelve GluTR subunits (heme/protein ratio of 1/12) | Acidithiobacillus ferrooxidans | |
NADP+ | - |
Acidithiobacillus ferrooxidans | |
NADPH | - |
Acidithiobacillus ferrooxidans |
General Information | Comment | Organism |
---|---|---|
metabolism | glutamyl-tRNA reductase (GluTR) is the key enzyme for heme biosynthesis. The flow of glutamyl-tRNA is diverted from heme biosynthesis towards protein synthesis under oxidative stress conditions. In the C5 pathway, 5-aminolevulinic acid is synthesized from Glu-tRNAGlu in two steps. First, the glutamate moiety of Glu-tRNAGlu is reduced to glutamate semialdehyde (GSA) by glutamyl-tRNA reductase (GluTR), and then GSA is converted to 5-aminolevulinic acid by the glutamate semialdehyde 1-2 aminomutase (GSAM) | Acidithiobacillus ferrooxidans |
physiological function | in chemolithoautotrophic bacteria like Acidithiobacillus ferrooxidans that use the C5 pathway to synthesize tetrapyrroles, high demand for Glu-tRNAGlu for heme biosynthesis is expected, due to the high cytochrome content required for respiration using poor electron donors, such as ferrous ions. This bacterium has a complex system of glutamyl-tRNA formation composed of two non-discriminating glutamyl-tRNA synthetases (GluRS1 and GluRS2) and up to four tRNAGlu isoacceptors, with GluRS1 serving as the main enzyme for Glu-tRNAGlu formation. Three out of four glutamyl-tRNAs can act as donors for both heme and protein synthesis, while the fourth is not a substrate of GluTR and likely acts exclusively in protein synthesis | Acidithiobacillus ferrooxidans |