UniProt functional annotation for P69910

UniProt code: P69910.

Organism: Escherichia coli (strain K12).
Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.
Function: Converts glutamate to gamma-aminobutyrate (GABA), consuming one intracellular proton in the reaction. The gad system helps to maintain a near-neutral intracellular pH when cells are exposed to extremely acidic conditions. The ability to survive transit through the acidic conditions of the stomach is essential for successful colonization of the mammalian host by commensal and pathogenic bacteria.
Catalytic activity: L-glutamate = 4-aminobutanoate + CO(2).
Cofactor: Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
Subunit: Homohexamer composed of three dimers. {ECO:0000269|PubMed:12912902}.
Subcellular location: Cytoplasm {ECO:0000269|PubMed:12912902}. Membrane {ECO:0000269|PubMed:12912902}. Note=Localized exclusively in the cytoplasm at neutral pH, but is recruited to the membrane when the pH falls.
Induction: By acidic conditions. Expression is regulated by a complex system involving RpoS, cAMP, CRP, EvgAS, H-NS, GadE, GadW and GadX. The level of involvement for each regulator varies depending upon the growth phase and the medium. {ECO:0000269|PubMed:10383761, ECO:0000269|PubMed:11976288, ECO:0000269|PubMed:12399493, ECO:0000269|PubMed:12446650, ECO:0000269|PubMed:12694615, ECO:0000269|PubMed:12867478, ECO:0000269|PubMed:12940989}.
Miscellaneous: Changing Lys-276 to Ala increases thermal stability and protease resistance. The unfolding temperature is increased by 11 degrees Celsius.
Similarity: Belongs to the group II decarboxylase family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.