Cloned (Comment) | Organism |
---|---|
gene yjbM, recombinant expression of His-tagged enzyme in Escherichia coli strain BL21(DE3) | Bacillus subtilis |
Crystallization (Comment) | Organism |
---|---|
purified enzyme in presence of ATP and GTP, 1 week, X-ray diffraction structure determination and analysis at 2.94 A resolution | Bacillus subtilis |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | alarmone synthesis in SAS1 proceeds in a highly cooperative manner | Bacillus subtilis | |
1.2 | - |
GDP | pH 7.5, 37°C, recombinant enzyme | Bacillus subtilis | |
1.7 | - |
GTP | pH 7.5, 37°C, recombinant enzyme | Bacillus subtilis | |
2 | - |
guanosine 3'-diphosphate 5'-triphosphate | pH 7.5, 37°C, recombinant enzyme | Bacillus subtilis | |
3 | - |
guanosine 3'-diphosphate 5'-diphosphate | pH 7.5, 37°C, recombinant enzyme | Bacillus subtilis |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required, binding structure analysis, overview | Bacillus subtilis |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + GDP | Bacillus subtilis | - |
AMP + guanosine 3'-diphosphate 5'-diphosphate | - |
? | |
ATP + GDP | Bacillus subtilis 168 | - |
AMP + guanosine 3'-diphosphate 5'-diphosphate | - |
? | |
ATP + GTP | Bacillus subtilis | - |
AMP + guanosine 3'-diphosphate 5'-triphosphate | - |
? | |
ATP + GTP | Bacillus subtilis 168 | - |
AMP + guanosine 3'-diphosphate 5'-triphosphate | - |
? | |
guanosine 3'-diphosphate 5'-diphosphate + H2O | Bacillus subtilis | - |
GDP + diphosphate | - |
? | |
guanosine 3'-diphosphate 5'-diphosphate + H2O | Bacillus subtilis 168 | - |
GDP + diphosphate | - |
? | |
guanosine 3'-diphosphate 5'-triphosphate + H2O | Bacillus subtilis | - |
GTP + diphosphate | - |
? | |
guanosine 3'-diphosphate 5'-triphosphate + H2O | Bacillus subtilis 168 | - |
GTP + diphosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bacillus subtilis | O31611 | gene yjbM | - |
Bacillus subtilis 168 | O31611 | gene yjbM | - |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography and gel filtration | Bacillus subtilis |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
ATP + GTP = AMP + guanosine 3'-diphosphate 5'-triphosphate | the catalytic pathway of (p)ppGpp synthesis involves a sequentially ordered substrate binding, activation of ATP in a strained conformation, and transfer of diphosphate through a nucleophilic substitution (SN2) reaction. pppGpp, but not ppGpp, positively regulates the enzyme at an allosteric site | Bacillus subtilis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + GDP | - |
Bacillus subtilis | AMP + guanosine 3'-diphosphate 5'-diphosphate | - |
? | |
ATP + GDP | - |
Bacillus subtilis 168 | AMP + guanosine 3'-diphosphate 5'-diphosphate | - |
? | |
ATP + GTP | - |
Bacillus subtilis | AMP + guanosine 3'-diphosphate 5'-triphosphate | - |
? | |
ATP + GTP | - |
Bacillus subtilis 168 | AMP + guanosine 3'-diphosphate 5'-triphosphate | - |
? | |
guanosine 3'-diphosphate 5'-diphosphate + H2O | - |
Bacillus subtilis | GDP + diphosphate | - |
? | |
guanosine 3'-diphosphate 5'-diphosphate + H2O | - |
Bacillus subtilis 168 | GDP + diphosphate | - |
? | |
guanosine 3'-diphosphate 5'-triphosphate + H2O | - |
Bacillus subtilis | GTP + diphosphate | - |
? | |
guanosine 3'-diphosphate 5'-triphosphate + H2O | - |
Bacillus subtilis 168 | GTP + diphosphate | - |
? | |
additional information | the enzyme is bifunctional showing synthase activity forming ppGpp and pppGpp, and hydrolase activity with the two compounds resulting in formation of GTP or GDP and diphosphate | Bacillus subtilis | ? | - |
? | |
additional information | the enzyme is bifunctional showing synthase activity forming ppGpp and pppGpp, and hydrolase activity with the two compounds resulting in formation of GTP or GDP and diphosphate | Bacillus subtilis 168 | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
homotetramer | domain structure and three-dimensional homology modelling, sequence comparisons, crystal structure analysis, overview | Bacillus subtilis |
Synonyms | Comment | Organism |
---|---|---|
(p)ppGpp synthetase | - |
Bacillus subtilis |
alarmone synthetase | - |
Bacillus subtilis |
SAS1 | - |
Bacillus subtilis |
small alarmone synthetase 1 | - |
Bacillus subtilis |
YjbM | - |
Bacillus subtilis |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Bacillus subtilis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Bacillus subtilis |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ATP | binding structure analysis, overview | Bacillus subtilis |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme belongs to the RSH superfamily, which controls concentrations of the alarmones (p)ppGpp (guanosine penta- or tetra-phosphate) | Bacillus subtilis |
additional information | mechanism and allosteric regulation of the highly cooperative enzyme from Bacillus subtilis, overview. Analysis of the catalytic mechanism of (p)ppGpp synthesis by oligomeric and highly cooperative small alarmone synthetase 1 (SAS1) at atomic resolution, structural and biochemical analysis reveals that only pppGpp, but not ppGpp, positively affects the activity of the enzyme | Bacillus subtilis |
physiological function | guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), collectively termed (p)ppGpp, act as alarmones that globally reprogram cellular physiology during various stress conditions. Enzymes of the RelA/SpoT homology (RSH) family synthesize (p)ppGpp by transferring diphosphate from ATP to GDP or GTP. ppGpp and pppGpp execute different functional roles | Bacillus subtilis |