An inducible riboflavin synthetase from a pseudomonad.

Riboflavin synthetase activity is induced in a strain of Pseudomonas fluorescens-putida intermediate only under conditions permitting an accumulation of compound P, a 2,4-dioxopteridine, in the medium. The effect of different amino acids and sugars on the production of compound P and riboflavin synthetase was determined. The enzyme was partially destroyed by ammonium sulphate fractionation. It is inhibited by heavy metal ions and PCMB. PCMB inhibition can be almost completely reversed by GSH.