The function and structure of the metal coordination sites within the glucocorticoid receptor DNA binding domain
| Autor: | Korszun Zr, Basavappa R, Luisi Bf, Keith R. Yamamoto, Sigler Pb, Leonard P. Freedman |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Zinc finger
Binding Sites Multidisciplinary HMG-box Stereochemistry Spectrum Analysis X-Rays Molecular Sequence Data Cobalt DNA DNA-binding domain Biology Peptide Fragments DNA binding site Zinc Receptors Glucocorticoid Glucocorticoid receptor Biochemistry Escherichia coli Amino Acid Sequence Binding site Transcription factor Cadmium Binding domain |
| Zdroj: | Nature. 334:543-546 |
| ISSN: | 1476-4687 0028-0836 |
| DOI: | 10.1038/334543a0 |
| Popis: | The glucocorticoid receptor enhances or represses transcription by binding to specific DNA sequences termed glucocorticoid response elements, or GREs1–5. Studies of cloned glucocorticoid receptors6–8 reveal that the protein is organized as functional domains, in an arrangement that appears to be common among members of the steroid receptor family9. A segment near the centre of the gene specifies DNA binding activity in vitro and contains two sequence motifs similar to 'zinc fingers' found in Xenopus transcription factor III A (TFIIIA)10. Such sequence motifs have been identified in nucleic acid binding proteins from a wide range of organisms11–13. Steroid receptor protein fingers are proposed to bind zinc through two pairs of conserved cysteine residues7,14,15.We report here that a protein of relative molecular mass 19,000 (Mr = 19K) encompassing the DNA-binding domain of the glucocorticoid receptor that has been overexpressed in Escherichia coli and purified to homogeneity reversibly ligates two Zn(II) or Cd(II) ions. We show that metal ions are required for specific DNA binding and proper folding. Using EXAFS (extended X-ray absorption fine structure) and visible light spectroscopies, we find that each Zn atom is coordinated in a tetrahedral arrangement by four cysteines. |
| Databáze: | OpenAIRE |
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