Ergothioneine is a secreted antioxidant in mycobacterium smegmatis

Emani, Carine Sao ; Williams, Monique J. ; Wiid, Ian J. ; Hiten, Nicholas F. ; Viljoen, Albertus J. ; Pietersen, Ray-Dean D. ; Van Helden, Paul D. ; Baker, Bienyameen (2013-07)

The original publication is available at

Publication of this article was funded by the Stellenbosch University Open Access Fund.


Ergothioneine (ERG) and mycothiol (MSH) are two low-molecular-weight thiols synthesized by mycobacteria. The role of MSH has been extensively investigated in mycobacteria; however, little is known about the role of ERG in mycobacterial physiology. In this study, quantification of ERG at various points in the growth cycle of Mycobacterium smegmatis revealed that a significant portion of ERG is found in the culture media, suggesting that it is actively secreted. A mutant of M. smegmatis lacking egtD (MSMEG_6247) was unable to synthesize ERG, confirming its role in ERG biosynthesis. Deletion of egtD from wild-type M. smegmatis and an MSH-deficient mutant did not affect their susceptibility to antibiotics tested in this study. The ERG- and MSH-deficient double mutant was significantly more sensitive to peroxide than either of the single mutants lacking either ERG or MSH, suggesting that both thiols play a role in protecting M. smegmatis against oxidative stress and that ERG is able to partly compensate for the loss of MSH.

Please refer to this item in SUNScholar by using the following persistent URL:
This item appears in the following collections: