Catalyzes the NAD-dependent conversion of D-erythrose 4-phosphate to 4-phosphoerythronate. D-erythrose 4-phosphate + H2O + NAD(+) = 4-phospho-D-erythronate + 2 H(+) + NADH Optimum pH is about 8.6. Optimum temperature is 50 degrees Celsius at pH 8.6. Relatively thermostable. Activity begins to decrease significantly when E4PDH is incubated at 50 degrees Celsius for 5 min. Cofactor biosynthesis; pyridoxine 5'-phosphate biosynthesis; pyridoxine 5'-phosphate from D-erythrose 4-phosphate: step 1/5. Homotetramer. Belongs to the glyceraldehyde-3-phosphate dehydrogenase family. Epd subfamily. Was originally (PubMed:2546007 and PubMed:2124629) thought to be a glyceraldehyde 3-phosphate dehydrogenase, but glyceraldehyde 3-phosphate is not an efficient substrate (PubMed:7751290 and PubMed:9182530).