Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 106, Issue 5, Pages 1572-1577Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0812596106
Keywords
protein oxidation; monothiol; SRP
Categories
Funding
- National Institute of General Medical Sciences [GMO41883, GMO550905]
- New England Biolabs
Ask authors/readers for more resources
Organisms have evolved elaborate systems that ensure the homeostasis of the thiol redox environment in their intracellular compartments. In Escherichia coli, the cytoplasm is kept under reducing conditions by the thioredoxins with the help of thioredoxin reductase and the glutaredoxins with the small molecule glutathione and glutathione reductase. As a result, disulfide bonds are constantly resolved in this compartment. In contrast to the cytoplasm, the periplasm of E. coli is maintained in an oxidized state by DsbA, which is recycled by DsbB. Thioredoxin 1, when exported to the periplasm turns from a disulfide bond reductase to an oxidase that, like DsbA, is dependent on DsbB. In this study we set out to investigate whether a subclass of the thioredoxin superfamily, the glutaredoxins, can become disulfide bond-formation catalysts when they are exported to the periplasm. We find that glutaredoxins can promote disulfide bond formation in the periplasm. However, contrary to the behavior of thioredoxin 1 in this environment, the glutaredoxins do so independently of DsbB. Furthermore, we show that glutaredoxin 3 requires the glutathione biosynthesis pathway for its function and can oxidize substrates with only a single active-site cysteine. Our data provides in vivo evidence suggesting that oxidized glutathione is present in the E. coli periplasm in biologically significant concentrations.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available