The Action Mode of the Ribosome-Inactivating Protein α-Sarcin
| Autor: | Luen Hwu, Dow-Tien Chen, Alan Lin, Kuan-Chun Huang |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Isopropyl Thiogalactoside
Models Molecular Reticulocytes RNase P Protein Conformation Endocrinology Diabetes and Metabolism Clinical Biochemistry Biology Ribosome Fungal Proteins Ribonucleases Mutant protein Endoribonucleases Escherichia coli Animals Pharmacology (medical) Molecular Biology Ribosome-inactivating protein Hydrolysis Biochemistry (medical) Ribonuclease T1 RNA Cell Biology General Medicine Protein tertiary structure Recombinant Proteins Biochemistry Mutation Rabbits Eukaryotic Ribosome Ribosomes |
| Zdroj: | Journal of Biomedical Science. 7:420-428 |
| ISSN: | 1423-0127 1021-7770 |
| DOI: | 10.1159/000025477 |
| Popis: | Based on the tertiary structure of the ribosome-inactivating protein alpha-sarcin, domains that are responsible for hydrolyzing ribosomes and naked RNA have been dissected. In this study, we found that the head-to-tail interaction between the first amino beta-strand and the last carboxyl beta-strand is not involved in catalyzing the hydrolysis of ribosomes or ribonucleic acids. Instead, a four-strand pleated beta-sheet is indispensable for catalyzing both substrates, suggesting that alpha-sarcin and ribonuclease T1 (RNase T1) share a similar catalytic center. The integrity of an amino beta-hairpin and that of the loop L3 in alpha-sarcin are crucial for recognizing and hydrolyzing ribosomes in vitro and in vivo. However, a mutant protein without the beta-hairpin structure, or with a disrupted loop L3, is still capable of digesting ribonucleic acids. The functional involvement of the beta-hairpin and the loop L3 in the sarcin stem/loop RNA of ribosomes is demonstrated by a docking model, suggesting that the two structures are in essence naturally designed to distinguish ribosome-inactivating proteins from RNase T1 to inactivate ribosomes. |
| Databáze: | OpenAIRE |
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