Possible cargo protein of a type 4B encapsulin nanocompartment (Probable). Active in the presence of NAD and NADP, prefers NADP (PubMed:2165475). D-glyceraldehyde 3-phosphate + NADP(+) + phosphate = (2R)-3-phospho-glyceroyl phosphate + H(+) + NADPH D-glyceraldehyde 3-phosphate + NAD(+) + phosphate = (2R)-3-phospho-glyceroyl phosphate + H(+) + NADH Insensitive to pentalenolactone, an inhibitor of bacterial and eukaryotic GAPDH. Activity in vitro is significantly stabilized by potassium citrate. Thermostable. Has a 44-minute half-life at 100 degrees Celsius. Carbohydrate degradation; glycolysis; pyruvate from D-glyceraldehyde 3-phosphate: step 1/5. Homotetramer. Its location in a locus with a type 4B encapsulin shell protein suggests it might be located in an encapsulin nanocompartment. Belongs to the glyceraldehyde-3-phosphate dehydrogenase family.