Succinate-semialdehyde dehydrogenase 1 (SSADH1, GabD1, EC=1.2.1.16) catalyzes the NADP(+)-dependent oxidation of succinate semialdehyde (SSA) to succinate. SSADH activity in Mycobacterium tuberculosis (Mtb) is encoded by both gabD1 (Rv0234c) and gabD2 (Rv1731). The Mtb GabD1 SSADH1 reportedly is an enzyme of the gamma-aminobutyrate shunt, which forms a functional link between two TCA half-cycles by converting alpha-ketoglutarate to succinate.