Crystallization (Comment) | Organism |
---|---|
enzyme hexamer X-ray diffraction structure determination and analysis at pH 4.6 and pH 7.6 | Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cl- | acts as positive allosteric modulators of GadB | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamate | Escherichia coli | - |
4-aminobutanoate + CO2 | - |
? | |
L-glutamate | Listeria monocytogenes | - |
4-aminobutanoate + CO2 | - |
? | |
L-glutamate | Levilactobacillus brevis | - |
4-aminobutanoate + CO2 | - |
? | |
L-glutamate | Levilactobacillus brevis ATCC 367 | - |
4-aminobutanoate + CO2 | - |
? | |
L-glutamate | Levilactobacillus brevis FO12005 | - |
4-aminobutanoate + CO2 | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
gene gadB | - |
Levilactobacillus brevis | A9ZM78 | single gene gadB | - |
Levilactobacillus brevis | Q03U69 | LVIS_0079; gene gadB | - |
Levilactobacillus brevis ATCC 367 | Q03U69 | LVIS_0079; gene gadB | - |
Levilactobacillus brevis FO12005 | A9ZM78 | single gene gadB | - |
Listeria monocytogenes | - |
gene gadB | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamate | - |
Escherichia coli | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | - |
Listeria monocytogenes | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | - |
Levilactobacillus brevis | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | the alpha-carboxyl group, leaving as CO2, is replaced by a cytoplasmic proton, yielding 4-aminobutanoate | Listeria monocytogenes | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | the alpha-carboxyl group, leaving as CO2, is replaced by a cytoplasmic proton, yielding 4-aminobutanoate | Levilactobacillus brevis | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | the alpha-carboxyl group, leaving as CO2, is thus replaced by a cytoplasmic proton, yielding 4-aminobutanoate | Escherichia coli | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | the alpha-carboxyl group, leaving as CO2, is thus replaced by a cytoplasmic proton, yielding 4-aminobutanoate | Levilactobacillus brevis | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | - |
Levilactobacillus brevis ATCC 367 | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | the alpha-carboxyl group, leaving as CO2, is thus replaced by a cytoplasmic proton, yielding 4-aminobutanoate | Levilactobacillus brevis ATCC 367 | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | - |
Levilactobacillus brevis FO12005 | 4-aminobutanoate + CO2 | - |
? | |
L-glutamate | the alpha-carboxyl group, leaving as CO2, is replaced by a cytoplasmic proton, yielding 4-aminobutanoate | Levilactobacillus brevis FO12005 | 4-aminobutanoate + CO2 | - |
? |
Subunits | Comment | Organism |
---|---|---|
hexamer | GadB is a trimer of dimers, in which monomers from each dimer belong to different layers, structure comparisons, overview | Escherichia coli |
tetramer | Lactobacillus brevis IFO12005 is dimeric in the inactive form and tetrameric in the active form | Levilactobacillus brevis |
Synonyms | Comment | Organism |
---|---|---|
GadB | - |
Escherichia coli |
GadB | - |
Listeria monocytogenes |
GadB | - |
Levilactobacillus brevis |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | dependent on | Escherichia coli | |
pyridoxal 5'-phosphate | dependent on | Listeria monocytogenes | |
pyridoxal 5'-phosphate | dependent on | Levilactobacillus brevis |
Organism | Comment | Expression |
---|---|---|
Escherichia coli | expression of the gadBC operon increases under conditions of respiratory stress | up |
General Information | Comment | Organism |
---|---|---|
evolution | clustal X-generated dendrogram of bacterial glutamate decarboxylases, overview | Escherichia coli |
evolution | clustal X-generated dendrogram of bacterial glutamate decarboxylases, overview | Listeria monocytogenes |
evolution | clustal X-generated dendrogram of bacterial glutamate decarboxylases, overview | Levilactobacillus brevis |
additional information | absence of a His residue near the C-terminus in Lactobacillus brevis GadB homologue LVIS_0079 | Levilactobacillus brevis |
additional information | at neutral pH the enzyme is in a compact conformation with access to the active site precluded by steric hindrance of some structural elements, a sequence of events lead to the conversion of GadB from the inactive into the active form and vice versa, structural determinants responsible for pH-dependent intracellular activation of GadB, overview. In its inactive form GadB has (i) the N-terminal residues 1-14 of each subunit mainly involved in dimerization and hexamerization, (ii) the C-terminal residues 452-466 ordered and protruding into the active site (with residues His465 and Thr466), like a plug, thus occupying the binding site of the physiological substrate glutamate, (iii) the beta-hairpin 300-313 contacting the C-terminal tail of the other subunit in the dimer as to hold it in place, structure comparisons, overview | Escherichia coli |
physiological function | the glutamate-dependent acid resistance (GDAR) system is by far the most potent acid resistance system in commensal and pathogenic Escherichia coli and requires the activity of intracellular glutamate decarboxylase GadB performing a proton-consuming decarboxylation reaction and the cognate antiporter GadC, which performs the glutamate/in/gamma-aminobutyrate/out electrogenic antiport, overview | Escherichia coli |
physiological function | the glutamate-dependent acid resistance (GDAR) system is by far the most potent acid resistance system in commensal and pathogenic Listeria monocytogenes and requires the activity of intracellular glutamate decarboxylase GadB performing a proton-consuming decarboxylation reaction and the cognate antiporter GadC, which performs the glutamate/in/gamma-aminobutyrate/out electrogenic antiport, overview | Listeria monocytogenes |