Activating Compound | Comment | Organism | Structure |
---|---|---|---|
additional information | GTP hydrolysis by EF-G gets strongly stimulated by the ribosome | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
F94L | site-directed mutagenesis, the mutant shows GTP hydrolysis kinetics similar to the wild-type | Escherichia coli |
H91A | site-directed mutagenesis, the mutant shows defective ribosome associated GTP hydrolysis and inorganic phosphate release | Escherichia coli |
H91E | site-directed mutagenesis, the mutant shows defective ribosome associated GTP hydrolysis and inorganic phosphate release | Escherichia coli |
H91Q | site-directed mutagenesis, the mutant is defective in inorganic phosphate release | Escherichia coli |
H91R | site-directed mutagenesis, the mutant shows defective ribosome associated GTP hydrolysis and inorganic phosphate release | Escherichia coli |
additional information | intrinsic GTP hydrolysis by EF-G is unaffected by the H91 and F94 mutations. H91 mutated EF-Gs show different degrees of defect in ribosome-stimulated GTP hydrolysis. H91 mutants show larger defects in Pi release than in GTP hydrolysis | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0081 | - |
GTP | in presence of 70S ribosome, H91E, pH 7.5, 37°C | Escherichia coli | |
0.0082 | - |
GTP | in presence of 70S ribosome, wild-type enzyme, pH 7.5, 37°C | Escherichia coli | |
0.0085 | - |
GTP | in presence of 70S ribosome, F94L, pH 7.5, 37°C | Escherichia coli | |
0.0106 | - |
GTP | in presence of 70S ribosome, H91A, pH 7.5, 37°C | Escherichia coli | |
0.0134 | - |
GTP | in presence of 70S ribosome, H91Q, pH 7.5, 37°C | Escherichia coli | |
0.0143 | - |
GTP | in presence of 70S ribosome, H91R, pH 7.5, 37°C | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
ribosome | - |
Escherichia coli | 5840 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required for catalysis | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | Escherichia coli | - |
GDP + phosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P0A6M8 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | - |
Escherichia coli | GDP + phosphate | - |
? |
Synonyms | Comment | Organism |
---|---|---|
EF-G | - |
Escherichia coli |
elongation factor G | - |
Escherichia coli |
translational GTPase | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.9 | - |
GTP | in presence of 70S ribosome, H91E, pH 7.5, 37°C | Escherichia coli | |
2 | 8 | GTP | in presence of 70S ribosome, H91A, pH 7.5, 37°C | Escherichia coli | |
27 | - |
GTP | in presence of 70S ribosome, H91R, pH 7.5, 37°C | Escherichia coli | |
170 | - |
GTP | in presence of 70S ribosome, F94L, pH 7.5, 37°C | Escherichia coli | |
174 | - |
GTP | in presence of 70S ribosome, H91Q, pH 7.5, 37°C | Escherichia coli | |
202 | - |
GTP | in presence of 70S ribosome, wild-type enzyme, pH 7.5, 37°C | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
evolution | elongation factor G (EF-G) belongs to the subfamily of translational G-proteins in the GTPase superfamily. All G-proteins share a nucleotide binding G domain, which contains distinct and highly conserved elements (G1-G5). The G3 sequence motif, switch II, is highly flexible and contains a DXXG sequence | Escherichia coli |
malfunction | intrinsic GTP hydrolysis by EF-G is unaffected by the H91 and F94 mutations. H91 mutated EF-Gs show different degrees of defect in ribosome-stimulated GTP hydrolysis. H91 mutants show larger defects in Pi release than in GTP hydrolysis | Escherichia coli |
additional information | a conserved histidine in switch-II of EF-G moderates release of inorganic phosphate. EF-G possesses a conserved histidine 91 at the apex of switch-II, which is implicated in GTPase activation and GTP hydrolysis, H91 facilitates phosphate release. In crystal structures of the ribosome bound EF-G-GTP a tight coupling between H91 and the gamma-phosphate of GTP can be seen. Following GTP hydrolysis, H91 flips about 140° in the opposite direction, probably with phosphate still coupled to it, promoting phosphate to detach from GDP and reach the inter-domain space of EF-G, which constitutes an exit path for the phosphate, molecular dynamics simulations, overview. Mg2+ ion plays a vital role in the process | Escherichia coli |
physiological function | elongation factor G (EF-G) is a translational GTPase responsible for tRNA-mRNA translocation | Escherichia coli |