Oxygen-insensitive nitroreductases NfsA and NfsB of Escherichia coli function under anaerobic conditions as lawsone-dependent Azo reductases.

ABSTRACT: Quinones can function as redox mediators in the unspecific anaerobic reduction of azo compounds by various bacterial species. These quinones are enzymatically reduced by the bacteria and the resulting hydroquinones then reduce in a purely chemical redox reaction the azo compounds outside of the cells. Recently, it has been demonstrated that the addition of lawsone (2-hydroxy-1,4-naphthoquinone) to anaerobically incubated cells of Escherichia coli resulted in a pronounced increase in the reduction rates of different sulfonated and polymeric azo compounds. In the present study it was attempted to identify the enzyme system(s) responsible for the reduction of lawsone by E. coli and thus for the lawsone-dependent anaerobic azo reductase activity. An NADH-dependent lawsone reductase activity wa

SUBMITTER: Rau J 

PROVIDER: S-EPMC161523 | biostudies-literature | 2003 Jun

REPOSITORIES: biostudies-literature