1o7u

RADIATION INDUCED TRYPAREDOXIN-I

spinqualitylabelsall models 1o7u, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1o7u is a 1 chain structure with sequence from Crithidia fasciculata. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1fg4, 1i5g, 1o6j, 1o81, 1oc8, 1oc9, 1ewx, 1ezk, 1o73, 1o85, 1o8w, 1o8x, 1qk8 Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Tryparedoxin (TryX) is a member of the thioredoxin (TrX) fold family involved in the regulation of oxidative stress in parasitic trypanosomatids. Like TrX, TryX carries a characteristic Trp-Cys-Xaa-Xaa-Cys motif, which positions a redox-active disulfide underneath a tryptophan lid. We report the structure of a Crithidia fasciculata tryparedoxin isoform (CfTryX2) in two crystal forms and compare them with structures determined previously. Efforts to chemically generate crystals of reduced TryX1 were unsuccessful, and we carried out a novel experiment to break the redox-active disulfide, formed between Cys-40 and Cys-43, utilizing the intense x-radiation from a third generation synchrotron undulator beamline. A time course study of the S-S bond cleavage is reported with the structure of a TryX1 C43A mutant as the control. When freed from the constraints of a disulfide link to Cys-43, Cys-40 pivots to become slightly more solvent-accessible. In addition, we have determined the structure of Trypanosoma brucei TryX, which, influenced by the molecular packing in the crystal lattice, displays a significantly different orientation of the active site tryptophan lid. This structural change may be of functional significance when TryX interacts with tryparedoxin peroxidase, the final protein in the trypanothione-dependent peroxidase pathway. Comparisons with chloroplast TrX and its substrate fructose 1,6-bisphosphate phosphatase suggest that this movement may represent a general feature of redox regulation in the trypanothione and thioredoxin peroxidase pathways. Tryparedoxins from Crithidia fasciculata and Trypanosoma brucei: photoreduction of the redox disulfide using synchrotron radiation and evidence for a conformational switch implicated in function.,Alphey MS, Gabrielsen M, Micossi E, Leonard GA, McSweeney SM, Ravelli RB, Tetaud E, Fairlamb AH, Bond CS, Hunter WN J Biol Chem. 2003 Jul 11;278(28):25919-25. Epub 2003 Apr 21. PMID:12707277 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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