| Autor: |
Basilion, J P, Rouault, T A, Massinople, C M, Klausner, R D, Burgess, W H |
| Zdroj: |
Proceedings of the National Academy of Sciences of the United States of America; January 1994, Vol. 91 Issue: 2 p574-578, 5p |
| Abstrakt: |
The iron-responsive element-binding protein (IRE-BP) binds to specific stem-loop RNA structures known as iron-responsive elements (IREs) present in a variety of cellular mRNAs (e.g., those encoding ferritin, erythroid 5-aminolevulinate synthase, and transferrin receptor). Expression of these genes is regulated by interaction with the IRE-BP. The IRE-BP is identical in sequence to cytosolic aconitase, and the function of the protein is determined by the presence or absence of an Fe-S cluster. The protein either functions as an active aconitase when the Fe-S cluster is present or as an RNA-binding protein when the protein lacks this cluster. Aconitase activity and IRE-binding activity are mutually exclusive, and interconversion between the two activities is determined by intracellular Fe concentrations. Mapping of the RNA-binding site of the IRE-BP by UV cross-linking studies defines a major contact site between IRE and protein in the active-site region. Modeling based on probable structural similarities between the previously crystallized mitochondrial aconitase and the IRE-BP predicts that these residues would be accessible to the IRE only were there a major change in the predicted conformation of the protein when cells are iron-depleted. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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