An Escherichia coli chromosomal ars operon homolog is functional in arsenic detoxification and is conserved in gram-negative bacteria

Sequencing and cloning of an arsenic inducible operon present in the chromosome of Escherichia coli using a lacZ transcriptional gene fusion library shows that this operon is analogous in terms of protein sequence and genetic organization to the plasma induced ars determinant. This ars operon is functionally significant in the detoxification of metalloid in Escherichia coli and its expression can be induced by exposure to sodium arsenite at 5 micro grams/liter. The experimental set up of the cloning and sequencing of an arsenic inducible operon is discussed.