Pseudomonas aeruginosacauses opportunistic infections and is resistant to most antibiotics. Ongoing efforts to generate much-needed new antibiotics include targeting enzymes that are vital forP. aeruginosabut are absent in mammals. One such enzyme, type II dehydroquinase (DHQase), catalyzes the interconversion of 3-dehydroquinate and 3-dehydroshikimate, a necessary step in the shikimate pathway. This step is vital for the proper synthesis of phenylalanine, tryptophan, tyrosine and other aromatic metabolites. The recombinant expression, purification and crystal structure of catalytically active DHQase fromP. aeruginosa(PaDHQase) are presented. Cubic crystals belonging to space groupF23, with unit-cell parametersa=b=c= 125.39 Å, were obtained by vapor diffusion in sitting drops and the structure was refined to anRfactor of 16% at 1.74 Å resolution. PaDHQase is a prototypical type II DHQase with the classical flavodoxin-like α/β topology.
