The yliA, -B, -C, and -D genes of Escherichia coli K-12 encode a novel glutathione importer with an ATP-binding cassette.

Glutathione protects cells and organisms from oxygen species and peroxides and is indispensable for aerobically living organisms. Moreover, it acts against xenobiotics and drugs by the formation and excretion of glutathione S conjugates. In this study, we show that the yliA, -B, -C, and -D genes of Escherichia coli K-12 encode a glutathione transporter with the ATP-binding cassette. The transporter imports extracellular glutathione into the cytoplasm in an ATP-dependent manner. This transporter, along with gamma-glutamyltranspeptidase, has an important role in E. coli growth with glutathione as a sole sulfur source.