Phosphorylation of shikimic acid by ultrasonic extracts of micro-organisms

Abstract

Shikimic-acid kinase catalyzes transphosphorylation from ATP to shikimic-acid. It is present in mutants and wild-type Escherichia coli. It is soluble, has an optimum pH of 7.0, exhibits a requirement for Mg2+ or Mn2+ ions, is not inhibited by 0.2 mM-phenylmercuric-acetate and is 55% inhibited by 3 mM-iodoacetate. Formation of the enzyme is not suppressed, and its activity is not inhibited by the ultimate products of the aromatic biosynthetic pathway. Shikimic acid 5-phosphate accumulated in the growth medium of Aerobacter aerogenes A 170-40 when grown in the presence of limiting amounts of the full aromatic supplement. Fivefold purification of the enzyme is described. The presence of the enzyme in extracts of a number of microorganisms capable of synthesizing aromatic amino-acids is reported. It is absent from extracts of microorganisms which are incapable of synthesizing these acids.