Interruption of the ferredoxin (flavodoxin) NADP+ oxidoreductase gene of Escherichia coli does not affect anaerobic growth but increases sensitivity to paraquat

Ferredoxin (flavodoxin) NADP+ oxidoreductase participates in methionine biosynthesis and in the function of two anaerobic enzymes, pyruvate formate-lyase and ribonucleotide reductase. We prepared insertion mutants of Escherichia coli lacking a functional enzyme. They do not require methionine and they grow well anaerobically, but they show increased sensitivity to paraquat.