Crystal Structure of Human Thioredoxin MutantCrystal Structure of Human Thioredoxin Mutant

Structural highlights

4oo4 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 0.97Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

THIO_HUMAN Participates in various redox reactions through the reversible oxidation of its active center dithiol to a disulfide and catalyzes dithiol-disulfide exchange reactions. Plays a role in the reversible S-nitrosylation of cysteine residues in target proteins, and thereby contributes to the response to intracellular nitric oxide. Nitrosylates the active site Cys of CASP3 in response to nitric oxide (NO), and thereby inhibits caspase-3 activity. Induces the FOS/JUN AP-1 DNA-binding activity in ionizing radiation (IR) cells through its oxidation/reduction status and stimulates AP-1 transcriptional activity.[1] [2] [3] [4] [5] ADF augments the expression of the interleukin-2 receptor TAC (IL2R/P55).[6] [7] [8] [9] [10]

Publication Abstract from PubMed

Thioredoxins reduce disulfide bonds and other thiol modifications in all cells, using a CXXC motif. Human thioredoxin 1 is unusual in that it codes for an additional three cysteines in its 105 amino acid sequence, each of which have been implicated in other reductive activities. Cys 62 and Cys 69 are buried in the protein interior and lie at either end of a short helix (helix 3), and yet can disulfide link under oxidizing conditions. Cys 62 is readily S-nitrosated, giving rise to a SNO modification, which is also buried. Here, we present two crystal structures of the C69S/C73S mutant protein under oxidizing (1.5 A) and reducing (1.1 A) conditions. In the oxidized structure, helix 3 is unraveled and displays a new conformation that is stabilized by a series of new hydrogen bonds and a disulfide link with Cys 62 in a neighboring molecule. The new conformation provides an explanation for how a completely buried residue can participate in SNO exchange reactions.

Crystal structure of human thioredoxin revealing an unraveled helix and exposed S- nitrosation site.,Weichsel A, Kem M, Montfort WR Protein Sci. 2010 Jul 26. PMID:020662007[11]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Jacquot JP, de Lamotte F, Fontecave M, Schurmann P, Decottignies P, Miginiac-Maslow M, Wollman E. Human thioredoxin reactivity-structure/function relationship. Biochem Biophys Res Commun. 1990 Dec 31;173(3):1375-81. PMID:2176490
  2. Hirota K, Matsui M, Iwata S, Nishiyama A, Mori K, Yodoi J. AP-1 transcriptional activity is regulated by a direct association between thioredoxin and Ref-1. Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):3633-8. PMID:9108029
  3. Wei SJ, Botero A, Hirota K, Bradbury CM, Markovina S, Laszlo A, Spitz DR, Goswami PC, Yodoi J, Gius D. Thioredoxin nuclear translocation and interaction with redox factor-1 activates the activator protein-1 transcription factor in response to ionizing radiation. Cancer Res. 2000 Dec 1;60(23):6688-95. PMID:11118054
  4. Mitchell DA, Marletta MA. Thioredoxin catalyzes the S-nitrosation of the caspase-3 active site cysteine. Nat Chem Biol. 2005 Aug;1(3):154-8. Epub 2005 Jul 10. PMID:16408020 doi:http://dx.doi.org/nchembio720
  5. Mitchell DA, Morton SU, Fernhoff NB, Marletta MA. Thioredoxin is required for S-nitrosation of procaspase-3 and the inhibition of apoptosis in Jurkat cells. Proc Natl Acad Sci U S A. 2007 Jul 10;104(28):11609-14. Epub 2007 Jul 2. PMID:17606900 doi:http://dx.doi.org/0704898104
  6. Jacquot JP, de Lamotte F, Fontecave M, Schurmann P, Decottignies P, Miginiac-Maslow M, Wollman E. Human thioredoxin reactivity-structure/function relationship. Biochem Biophys Res Commun. 1990 Dec 31;173(3):1375-81. PMID:2176490
  7. Hirota K, Matsui M, Iwata S, Nishiyama A, Mori K, Yodoi J. AP-1 transcriptional activity is regulated by a direct association between thioredoxin and Ref-1. Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):3633-8. PMID:9108029
  8. Wei SJ, Botero A, Hirota K, Bradbury CM, Markovina S, Laszlo A, Spitz DR, Goswami PC, Yodoi J, Gius D. Thioredoxin nuclear translocation and interaction with redox factor-1 activates the activator protein-1 transcription factor in response to ionizing radiation. Cancer Res. 2000 Dec 1;60(23):6688-95. PMID:11118054
  9. Mitchell DA, Marletta MA. Thioredoxin catalyzes the S-nitrosation of the caspase-3 active site cysteine. Nat Chem Biol. 2005 Aug;1(3):154-8. Epub 2005 Jul 10. PMID:16408020 doi:http://dx.doi.org/nchembio720
  10. Mitchell DA, Morton SU, Fernhoff NB, Marletta MA. Thioredoxin is required for S-nitrosation of procaspase-3 and the inhibition of apoptosis in Jurkat cells. Proc Natl Acad Sci U S A. 2007 Jul 10;104(28):11609-14. Epub 2007 Jul 2. PMID:17606900 doi:http://dx.doi.org/0704898104
  11. Weichsel A, Kem M, Montfort WR. Crystal structure of human thioredoxin revealing an unraveled helix and exposed S- nitrosation site. Protein Sci. 2010 Jul 26. PMID:20662007 doi:10.1002/pro.455

4oo4, resolution 0.97Å

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