Purity > 90% as determined by SDS-PAGE. MW: 56.7kDa. Full Length: 1-466aa. N-terminal 6xHis-tagged. Escherichia coli (strain K12). Converts glutamate to gamma-aminobutyrate (GABA), consuming one intracellular proton in the reaction. The gad syst helps to maintain a near-neutral intracellular pH when cells are exposed to extrely 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.