|Title||The Corynebacterium glutamicum mycothiol peroxidase is a reactive oxygen species-scavenging enzyme that shows promiscuity in thiol redox control.|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Pedre, B., I. Van Molle, A. F. Villadangos, K. Wahni, D. Vertommen, L. Turell, H. Erdogan, L. M. Mateos, and J. Messens|
|Date Published||2015 Jun|
|Keywords||Bacterial Proteins, Corynebacterium glutamicum, Cysteine, Disulfides, Glycopeptides, Hydrogen Peroxide, Inositol, Kinetics, Molecular Sequence Data, Oxidation-Reduction, Oxidative Stress, Oxidoreductases, Peroxidases, Reactive Oxygen Species, Sequence Analysis, Protein, Sulfhydryl Compounds, Thioredoxins|
Cysteine glutathione peroxidases (CysGPxs) control oxidative stress levels by reducing hydroperoxides at the expense of cysteine thiol (-SH) oxidation, and the recovery of their peroxidatic activity is generally accomplished by thioredoxin (Trx). Corynebacterium glutamicum mycothiol peroxidase (Mpx) is a member of the CysGPx family. We discovered that its recycling is controlled by both the Trx and the mycothiol (MSH) pathway. After H2 O2 reduction, a sulfenic acid (-SOH) is formed on the peroxidatic cysteine (Cys36), which then reacts with the resolving cysteine (Cys79), forming an intramolecular disulfide (S-S), which is reduced by Trx. Alternatively, the sulfenic acid reacts with MSH and forms a mixed disulfide. Mycoredoxin 1 (Mrx1) reduces the mixed disulfide, in which Mrx1 acts in combination with MSH and mycothiol disulfide reductase as a biological relevant monothiol reducing system. Remarkably, Trx can also take over the role of Mrx1 and reduce the Mpx-MSH mixed disulfide using a dithiol mechanism. Furthermore, Mpx is important for cellular survival under H2 O2 stress, and its gene expression is clearly induced upon H2 O2 challenge. These findings add a new dimension to the redox control and the functioning of CysGPxs in general.
|Alternate Journal||Mol. Microbiol.|
The Corynebacterium glutamicum mycothiol peroxidase is a reactive oxygen species-scavenging enzyme that shows promiscuity in thiol redox control.