E. coli nitroreductase
E. coli nitroreductase is a flavoprotein found in the bacteria Escherichia coli. It catalyses the reduction of nitro groups in a wide range of substrates to produce the corresponding hydroxylamine. Although its role in vivo is unclear, it has been identified as useful in the metabolism of a number of prodrugs in anti-cancer gene therapy.
There are at least two oxygen-insensitive nitroreductases in E. coli. The major one is NfsA. The other is NfsB.