| Structural highlights
4dss is a 2 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Related: | 4dsq, 4dsr |
| Gene: | AHP1, L2916, L9354.5, YLR109W (Saccharomyces cerevisiae), G7746, TRX1, TRX2, YGR209C (Saccharomyces cerevisiae) |
| Activity: | Peroxiredoxin, with EC number 1.11.1.15 |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[TRX2_YEAST] Participates as a hydrogen donor in redox reactions through the reversible oxidation of its active center dithiol to a disulfide, accompanied by the transfer of 2 electrons and 2 protons. It is involved in many cellular processes, including deoxyribonucleotide synthesis, repair of oxidatively damaged proteins, protein folding, sulfur metabolism, and redox homeostasis. Thioredoxin-dependent enzymes include phosphoadenosine-phosphosulfate reductase MET16, alkyl-hydroperoxide reductase DOT5, thioredoxin peroxidases TSA1 and TSA2, alkyl hydroperoxide reductase AHP1, and peroxiredoxin HYR1. Thioredoxin is also involved in protection against reducing stress. As part of the LMA1 complex, it is involved in the facilitation of vesicle fusion such as homotypic vacuole and ER-derived COPII vesicle fusion with the Golgi. This activity does not require the redox mechanism. Through its capacity to inactivate the stress response transcription factor YAP1 and its regulator the hydroperoxide stress sensor HYR1, it is involved in feedback regulation of stress response gene expression upon oxidative stress.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Publication Abstract from PubMed
Peroxiredoxins (Prxs) are thiol-specific antioxidant proteins that protect cells against reactive oxygen species and are involved in cellular signaling pathways. Alkyl hydroperoxide reductase Ahp1 belongs to the Prx5 subfamily and is a two-cysteine (2-Cys) Prx that forms an intermolecular disulfide bond. Enzymatic assays and bioinformatics enabled us to re-assign the peroxidatic cysteine (C(P)) to Cys-62 and the resolving cysteine (C(R)) to Cys-31 but not the previously reported Cys-120. Thus Ahp1 represents the first 2-Cys Prx with a peroxidatic cysteine after the resolving cysteine in the primary sequence. We also found the positive cooperativity of the substrate t-butyl hydroperoxide binding to Ahp1 homodimer at a Hill coefficient of approximately 2, which enabled Ahp1 to eliminate hydroperoxide at much higher efficiency. To gain the structural insights into the catalytic cycle of Ahp1, we determined the crystal structures of Ahp1 in the oxidized, reduced, and Trx2-complexed forms at 2.40, 2.91, and 2.10 A resolution, respectively. Structural superposition of the oxidized to the reduced form revealed significant conformational changes at the segments containing C(P) and C(R). An intermolecular C(P)-C(R) disulfide bond crossing the A-type dimer interface distinguishes Ahp1 from other typical 2-Cys Prxs. The structure of the Ahp1-Trx2 complex showed for the first time how the electron transfers from thioredoxin to a peroxidase with a thioredoxin-like fold. In addition, site-directed mutagenesis in combination with enzymatic assays suggested that the peroxidase activity of Ahp1 would be altered upon the urmylation (covalently conjugated to ubiquitin-related modifier Urm1) of Lys-32.
Structural Snapshots of Yeast Alkyl Hydroperoxide Reductase Ahp1 Peroxiredoxin Reveal a Novel Two-cysteine Mechanism of Electron Transfer to Eliminate Reactive Oxygen Species.,Lian FM, Yu J, Ma XX, Yu XJ, Chen Y, Zhou CZ J Biol Chem. 2012 May 18;287(21):17077-87. Epub 2012 Apr 2. PMID:22474296[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Schwenn JD, Krone FA, Husmann K. Yeast PAPS reductase: properties and requirements of the purified enzyme. Arch Microbiol. 1988;150(4):313-9. PMID:3060034
- ↑ Xu Z, Mayer A, Muller E, Wickner W. A heterodimer of thioredoxin and I(B)2 cooperates with Sec18p (NSF) to promote yeast vacuole inheritance. J Cell Biol. 1997 Jan 27;136(2):299-306. PMID:9015301
- ↑ Xu Z, Sato K, Wickner W. LMA1 binds to vacuoles at Sec18p (NSF), transfers upon ATP hydrolysis to a t-SNARE (Vam3p) complex, and is released during fusion. Cell. 1998 Jun 26;93(7):1125-34. PMID:9657146
- ↑ Park SG, Cha MK, Jeong W, Kim IH. Distinct physiological functions of thiol peroxidase isoenzymes in Saccharomyces cerevisiae. J Biol Chem. 2000 Feb 25;275(8):5723-32. PMID:10681558
- ↑ Lee J, Spector D, Godon C, Labarre J, Toledano MB. A new antioxidant with alkyl hydroperoxide defense properties in yeast. J Biol Chem. 1999 Feb 19;274(8):4537-44. PMID:9988687
- ↑ Delaunay A, Isnard AD, Toledano MB. H2O2 sensing through oxidation of the Yap1 transcription factor. EMBO J. 2000 Oct 2;19(19):5157-66. PMID:11013218 doi:http://dx.doi.org/10.1093/emboj/19.19.5157
- ↑ Delaunay A, Pflieger D, Barrault MB, Vinh J, Toledano MB. A thiol peroxidase is an H2O2 receptor and redox-transducer in gene activation. Cell. 2002 Nov 15;111(4):471-81. PMID:12437921
- ↑ Trotter EW, Grant CM. Thioredoxins are required for protection against a reductive stress in the yeast Saccharomyces cerevisiae. Mol Microbiol. 2002 Nov;46(3):869-78. PMID:12410842
- ↑ Grant CM. Role of the glutathione/glutaredoxin and thioredoxin systems in yeast growth and response to stress conditions. Mol Microbiol. 2001 Feb;39(3):533-41. PMID:11169096
- ↑ Elazar Z, Scherz-Shouval R, Shorer H. Involvement of LMA1 and GATE-16 family members in intracellular membrane dynamics. Biochim Biophys Acta. 2003 Aug 18;1641(2-3):145-56. PMID:12914955
- ↑ Lian FM, Yu J, Ma XX, Yu XJ, Chen Y, Zhou CZ. Structural Snapshots of Yeast Alkyl Hydroperoxide Reductase Ahp1 Peroxiredoxin Reveal a Novel Two-cysteine Mechanism of Electron Transfer to Eliminate Reactive Oxygen Species. J Biol Chem. 2012 May 18;287(21):17077-87. Epub 2012 Apr 2. PMID:22474296 doi:10.1074/jbc.M112.357368
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