MetaCyc Pathway: glutathione amide metabolism

Enzyme View:

Pathway diagram: glutathione amide metabolism

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Superclasses: Biosynthesis Cofactors, Prosthetic Groups, Electron Carriers Biosynthesis Reductants Biosynthesis

Some taxa known to possess this pathway include ? : Allochromatium vinosum , Marichromatium gracile

Expected Taxonomic Range: Bacteria

glutathione amide (GASH) is one of several glutathione-related compounds that are found in prokaryotes [Fahey01]. The compound is produced at milimolar levels by the purple photosynthetic bacteria Allochromatium vinosum and Marichromatium gracile [Bartsch96].

A GASH-dependent peroxidase has been identified in Marichromatium gracile. The enzyme belongs to the peroxiredoxin family, even though other members of the family are thioredoxin-dependent. Since this enzyme is capable of reducing hydrogen peroxide, and since Marichromatium gracile, while an anaerobic organism, is capable of surviving under microaerobic conditions, it was suggested that glutathione amide mediated peroxide detoxification represents an early adaptation for fighting oxidative stress [Vergauwen01].

During the reduction of peroxide, GASH forms a disulfide, similar to glutathione disulfide. However, GASH is maintained in a reduced state by a dedicated glutathione amide reductase (GAR), which converts it back to the reduced form, utilizing NADH [Vergauwen01].

When grown on hydrogen sulfide as a hydrogen donor, most of the GASH is converted to a perthiol form (GASSH), suggesting that it may be involved in sulfide metabolism in the organism, perhaps assiting the import of sufide into the cell, where it forms sulfur globules [Pott98, Bartsch96].

Another amide derivative of glutathione is glutathionylspermidine (see glutathionylspermidine biosynthesis).

Created 08-Aug-2005 by Caspi R , SRI International


Bartsch96: Bartsch RG, Newton GL, Sherrill C, Fahey RC (1996). "Glutathione amide and its perthiol in anaerobic sulfur bacteria." J Bacteriol 178(15);4742-6. PMID: 8755912

Fahey01: Fahey RC (2001). "Novel thiols of prokaryotes." Annu Rev Microbiol 2001;55;333-56. PMID: 11544359

Pott98: Pott AS, Dahl C (1998). "Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur." Microbiology 144 ( Pt 7);1881-94. PMID: 9695921

Vergauwen01: Vergauwen B, Pauwels F, Jacquemotte F, Meyer TE, Cusanovich MA, Bartsch RG, Van Beeumen JJ (2001). "Characterization of glutathione amide reductase from Chromatium gracile. Identification of a novel thiol peroxidase (Prx/Grx) fueled by glutathione amide redox cycling." J Biol Chem 276(24);20890-7. PMID: 11399772

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Vergauwen02: Vergauwen B, Van Petegem F, Remaut H, Pauwels F, Van Beeumen JJ (2002). "Crystallization and preliminary X-ray crystallographic analysis of glutathione amide reductase from Chromatium gracile." Acta Crystallogr D Biol Crystallogr 58(Pt 2);339-40. PMID: 11807270

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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