Glutaredoxin

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Glutaredoxin
Identifiers
Symbol	Glutaredoxin
Pfam	PF00462
InterPro	IPR002109
PROSITE	PDOC00173
SCOP	1kte
OPM family	139
OPM protein	1z9h
Available PDB structures: 1ykaA:17-81 1wikA:250-314 2cq9A:69-131 2flsA:69-131 1jhb :15-80 1b4qA:15-80 1kte :15-80 1nm3B:172-230 3grx :4-63 1ilbA:4-63 1fovA:4-63 1ego :3-69 1egr :3-69 1grx :3-69 1qfnA:3-69 1aazB:2-76 1de2A:2-76 1de1A:2-76 1aba :2-76 1nhoA:5-66 1fo5A:6-67 1j08A:138-162 1a8l :138-162 1r7hB:3-61 1h75A:3-61 1z9hB:102-152 1hyuA:155-181 1zypB:155-181 1zynB:155-181

Glutaredoxins^[1][2][3] are small redox enzymes of approximately one hundred amino-acid residues which use glutathione as a cofactor. Glutaredoxins are oxidised by substrates, and reduced non-enzymatically by glutathione. In contrast to thioredoxins, which are reduced by thioredoxin reductase, no oxidoreductase exists that specifically reduces glutaredoxins. Instead, oxidized glutathione is regenerated by glutathione reductase. Together these components compose the glutathione system^[4].

Glutaredoxins function as electron carriers in the glutathione-dependent synthesis of deoxyribonucleotides by the enzyme ribonucleotide reductase. Like thioredoxin, which functions in a similar way, glutaredoxin possesses an active centre disulfide bond^[5]. It exists in either a reduced or an oxidized form where the two cysteine residues are linked in an intramolecular disulfide bond.

Glutaredoxin has been sequenced in a variety of species. On the basis of extensive sequence similarity, it has been proposed^[6] that Vaccinia virus protein O2L is most probably a glutaredoxin. Finally, it must be noted that Bacteriophage T4 thioredoxin seems also to be evolutionary related. In position 5 of the pattern T4 thioredoxin has Val instead of Pro.

Contents 1 Subfamilies 2 Human proteins containing this domain 3 References 4 External links

[edit] Subfamilies

• Glutaredoxin subgroup IPR014025

[edit] Human proteins containing this domain

GLRX; GLRX2; GLRX3; GLRX5; PTGES2; TXNL3;

[edit] References

1. ^ Holmgren A, Gleason FK (1988). "Thioredoxin and related proteins in procaryotes". FEMS Microbiol. Rev. 4 (4): 271–297. PMID 3152490. 
2. ^ Holmgren A (1988). "Thioredoxin and glutaredoxin: small multi-functional redox proteins with active-site disulfide bonds". Biochem. Soc. Trans. 16 (2): 95–96. PMID 3286320. 
3. ^ Holmgren A (1989). "Thioredoxin and glutaredoxin systems". J. Biol. Chem. 264 (24): 13963–13966. PMID 2668278. 
4. ^ Holmgren A, Fernandes AP (2004). "Glutaredoxins: glutathione-dependent redox enzymes with functions far beyond a simple thioredoxin backup system". Antioxid. Redox. Signal. 6 (1): 63–74. doi:10.1089/152308604771978354. PMID 14713336. 
5. ^ Nilsson L, Foloppe N (2004). "The glutaredoxin -C-P-Y-C- motif: influence of peripheral residues". Structure 12 (2): 289–300. PMID 14962389. 
6. ^ Johnson GP, Goebel SJ, Perkus ME, Davis SW, Winslow JP, Paoletti E (1991). "Vaccinia virus encodes a protein with similarity to glutaredoxins". Virology 181 (1): 378–381. doi:10.1016/0042-6822(91)90508-9. PMID 1994586. 

[edit] External links

Enzyme database entry