1 PHD Aspartyl phosphate 1.000 2 ZNS 4-oxo-4-(phosphonooxy)butanoic acid 0.923 3 4TP 4-hydroxy-L-threonine-5-monophosphate 0.857 4 DER D-4-phosphoerythronic acid 0.733 5 DEZ 4-phospho-D-erythronate 0.733