Dihydrodipicolinate synthase (DHDPS) is a key enzyme in lysine biosynthesis. It catalyzes the aldol condensation of L-aspartate-beta- semialdehyde and pyruvate to dihydropicolinic acid via a Schiff base formation between pyruvate and a lysine residue. The functional enzyme is a homotetramer consisting of a dimer of dimers. DHDPS is member of dihydrodipicolinate synthase family that comprises several pyruvate-dependent class I aldolases that use the same catalytic step to catalyze different reactions in different pathways.