of DHDPS from different sources are well-conserved. The structure takes the form of a homotetramer, in which 2 monomers are related by an approximate 2-fold symmetry . [ 1 ] Each monomer comprises 2 domains: an 8-fold alpha-/beta-barrel, and a C-terminal alpha-helical domain. The fold resembles that of N-acetylneuraminate lyase. The