Substrate ambiguity of 3-deoxy-D-manno-octulosonate 8-phosphate synthase from Neisseria gonorrhoeae revisited

Homogeneous, recombinant 3-deoxy-D-manno-octulosonate I-phosphate synthase from Neisseria gonorrhoeae is shown to catalyze the formation of 3-deoxy-D- manno-octulosonate 8-phosphate from phosphoenolpyruvate and D-arabinose 5-p hosphate as determined from H-1-nuclear magnetic resonance analysis of the product. This enzyme does not catalyze the condensation of D-erythrose 4-ph osphate and phosphoenolpyruvate to form 3-deoxy-D-ribo-heptulosonate 7-phos phate, as was previously reported (P. S. Sabramaniam, G. Xie, T. Xia, and R A. Jensen, J. Bacteriol. 180:119-127, 1998).