Enhancing Corynebacterium glutamicum robustness by over-expressing a gene, mshA, for mycothiol glycosyltransferase.

Over-expression of the gene, mshA, coding for mycothiol glycosyl transferase improved the robustness of Corynebacterium glutamicum to various stresses. Intracellular mycothiol (MSH) content was increased by 114 % in WT(pXMJ19-mshA) compared to WT(pXMJ19). Survival rates increased by 44, 39, 90, 77, 131, 87, 52, 47, 57, 85 and 33 % as compared to WT(pXMJ19) under stress by H2O2 (40 mM), methylglyoxal (5.

NrdH Redoxin enhances resistance to multiple oxidative stresses by acting as a peroxidase cofactor in Corynebacterium glutamicum.

NrdH redoxins are small protein disulfide oxidoreductases behaving like thioredoxins but sharing a high amino acid sequence similarity to glutaredoxins. Although NrdH redoxins are supposed to be another candidate in the antioxidant system, their physiological roles in oxidative stress remain unclear. In this study, we confirmed that the Corynebacterium glutamicum NrdH redoxin catalytically reduces the disulfides in the class Ib ribonucleotide reductases (RNR), insulin and 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB), by exclusively receiving electrons from thioredoxin reductase.

Physiological roles of mycothiol in detoxification and tolerance to multiple poisonous chemicals in Corynebacterium glutamicum.

Mycothiol (MSH) plays important roles in maintaining cytosolic redox homeostasis and in adapting to reactive oxygen species in the high-(G + C)-content Gram-positive Actinobacteria. However, its physiological roles are ill defined compared to glutathione, the functional analog of MSH in Gram-negative bacteria and most eukaryotes. In this research, we explored the impact of intracellular MSH on cellular physiology by using MSH-deficient mutants in the model organism Corynebacterium glutamicum.