2LQQ

Oxidized Mrx1

Summary for 2LQQ

• Entry DOI: 10.2210/pdb2lqq/pdb
• Related: 2lqo
• NMR Information: BMRB: 18325
• Descriptor: Putative glutaredoxin Rv3198.1/MT3292 (1 entity in total)
• Functional Keywords: trx fold, oxidoreductase
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 1
• Total formula weight: 10030.32

Authors

Buts, L.,Van Laer, K.,Messens, J. (deposition date: 2012-03-11, release date: 2012-10-10, Last modification date: 2023-06-14)

Primary citation

Van Laer, K.,Buts, L.,Foloppe, N.,Vertommen, D.,Van Belle, K.,Wahni, K.,Roos, G.,Nilsson, L.,Mateos, L.M.,Rawat, M.,van Nuland, N.A.,Messens, J.
Mycoredoxin-1 is one of the missing links in the oxidative stress defence mechanism of Mycobacteria.
Mol.Microbiol., 86:787-804, 2012

PubMed Abstract: To survive hostile conditions, the bacterial pathogen Mycobacterium tuberculosis produces millimolar concentrations of mycothiol as a redox buffer against oxidative stress. The reductases that couple the reducing power of mycothiol to redox active proteins in the cell are not known. We report a novel mycothiol-dependent reductase (mycoredoxin-1) with a CGYC catalytic motif. With mycoredoxin-1 and mycothiol deletion strains of Mycobacterium smegmatis, we show that mycoredoxin-1 and mycothiol are involved in the protection against oxidative stress. Mycoredoxin-1 acts as an oxidoreductase exclusively linked to the mycothiol electron transfer pathway and it can reduce S-mycothiolated mixed disulphides. Moreover, we solved the solution structures of oxidized and reduced mycoredoxin-1, revealing a thioredoxin fold with a putative mycothiol-binding site. With HSQC snapshots during electron transport, we visualize the reduction of oxidized mycoredoxin-1 as a function of time and find that mycoredoxin-1 gets S-mycothiolated on its N-terminal nucleophilic cysteine. Mycoredoxin-1 has a redox potential of -218 mV and hydrogen bonding with neighbouring residues lowers the pKa of its N-terminal nucleophilic cysteine. Determination of the oxidized and reduced structures of mycoredoxin-1, better understanding of mycothiol-dependent reactions in general, will likely give new insights in how M. tuberculosis survives oxidative stress in human macrophages.

PubMed: 22970802
DOI: 10.1111/mmi.12030

Experimental method

SOLUTION NMR