Glutamic-pyruvate transaminase 2 (alanine aminotransferase 2) (GPT2) catalyzes the reversible reaction of alanine and 2-oxoglutarate (alpha-ketoglutarate) to form pyruvate and glutamate (Yang et al. 2002). Unpublished crystallographic data are consistent with a homodimeric structure for the enzyme with one molecule of pyridoxal phosphate associated with each monomer (PDB 3IHJ). Recent studies of organelles purified from cultured human muscle cells suggest that GPT2 is localized to mitochondria (Glinghammar et al. 2009).