Putrescine is an organic chemical produced when amino acids are broken down in organsisms, both living and dead. It can be used as a carbon and nitrogen source in E. coli, and is broken down into gamma-aminobutyric acid (GABA). In this pathway, GABA from putrescine degradation reacts with oxoglutaric acid in a reversible reaction catalyzed by 4-aminobutyrate aminotransferase. This reaction forms succinic acid semialdehyde, as well as L-glutamic acid as a byproduct. Succinic acid semialdehyde is then converted to succinic acid in a reaction catalyzed by succinate-semialdehyde dehydrogenase, using NAD as a cofactor. Succinic acid can then be used by the bacteria in the TCA cycle.

4-Aminobutanoate Degradation I References