Bacterial mechanisms of reversible protein S-thiolation: structural and mechanistic insights into mycoredoxins

Haike Antelmann, Chris J. Hamilton

    Research output: Contribution to journalArticlepeer-review

    10 Citations (Scopus)

    Abstract

    Mycobacteria produce millimolar concentrations of mycothiol (MSH) as their major low molecular weight thiol redox buffer. MSH-deficient mutants display increased sensitivity towards reactive oxygen, nitrogen and electrophilic species as well as alkylating agents and antibiotics. MSH is maintained in its reduced thiol state by the NADPH-dependent mycothiol disulphide reductase (Mtr). However, the redoxin that uses the MSH/Mtr/NADPH pathway for reduction of MSH-mixed protein disulphides, formed during oxidative stress, has long remained unknown. In this issue, Van Laer et al. report that MSH provides the reducing power for mycoredoxin-1 (Mrx1) in reduction of synthetic MSH-mixed disulphides. The reduced (dithiol) and oxidized (disulphide) solution structures of Mrx1 have been solved by nuclear magnetic resonance (NMR) spectroscopy. NMR time course experiments have also demonstrated the transient S-mycothiolation of the active site Cys14 of oxidized Mrx1 during reduction by the MSH/Mtr/NADPH electron pathway. The paper opens a new era of research to identify S-mycothiolated Mrx1 substrates and the function of MSH in redox regulation and virulence in Mycobacterium tuberculosis.
    Original languageEnglish
    Pages (from-to)759-764
    Number of pages6
    JournalMolecular Microbiology
    Volume86
    Issue number4
    Early online date24 Sept 2012
    DOIs
    Publication statusPublished - Nov 2012

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