HspBP1, an Hsp70 cochaperone, has two structural domains and is capable of altering the conformation of the Hsp70 ATPase domain
| Autor: | Deborah A. Raynes, Vince Guerriero, Catherine McLellan |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Reticulocytes
EGF-like domain Protein Conformation Protein domain Protein Renaturation Biology Biochemistry Mass Spectrometry Protein Structure Secondary HAMP domain Structure-Activity Relationship Adenosine Triphosphate EVH1 domain Chymotrypsin Humans HSP70 Heat-Shock Proteins Trypsin Luciferases Molecular Biology Adaptor Proteins Signal Transducing Adenosine Triphosphatases Circular Dichroism DHR1 domain Cell Biology Exons Recombinant Proteins Mutagenesis Insertional Cyclic nucleotide-binding domain DEP domain Mutagenesis Site-Directed Endopeptidase K Carrier Proteins Binding domain |
| Zdroj: | The Journal of biological chemistry. 278(21) |
| ISSN: | 0021-9258 |
| Popis: | We present here the first structural information for HspBP1, an Hsp70 cochaperone. Using circular dichroism, HspBP1 was determined to be 35% helical. Although HspBP1 is encoded by seven exons, limited proteolysis shows that it has only two structural domains. Domain I, amino acids 1–83, is largely unstructured. Domain II, amino acids 84–359, is predicted to be 43% helical using circular dichroism. Using limited proteolysis we have also shown that HspBP1 association changes the conformation of the ATPase domain of Hsp70. Only domain II of HspBP1 is required to bring about this conformational change. Truncation mutants of HspBP1 were tested for their ability to inhibit the renaturation of luciferase and bind to Hsp70 in reticulocyte lysate. A carboxyl terminal truncation mutant that was slightly longer than domain I was inactive in these assays, but domain II was sufficient to perform both functions. Domain II was less active than full-length HspBP1 in these assays, and addition of amino acids from domain I improved both functions. These studies show that HspBP1 domain II can bind Hsp70, change the conformation of the ATPase domain, and inhibit Hsp70-associated protein folding. |
| Databáze: | OpenAIRE |
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