Structural basis for substrate helix remodeling and cleavage loop activation in the Varkud satellite ribozyme
| Autor: | Nikolai B Suslov, Joseph A. Piccirilli, Saurja DasGupta |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Models Molecular RNA Folding Stereochemistry 010402 general chemistry Cleavage (embryo) 01 natural sciences Biochemistry Catalysis Article Protein Structure Secondary Substrate Specificity 03 medical and health sciences Colloid and Surface Chemistry Protein structure Endoribonucleases RNA Catalytic Nuclear Magnetic Resonance Biomolecular biology GIR1 branching ribozyme Chemistry Ribozyme General Chemistry 0104 chemical sciences GlmS glucosamine-6-phosphate activated ribozyme Crystallography 030104 developmental biology biology.protein Biocatalysis RNA RNA Cleavage Hairpin ribozyme VS ribozyme |
| Popis: | The Varkud satellite (VS) ribozyme catalyzes site-specific RNA cleavage and ligation reactions. Recognition of the substrate involves a kissing loop interaction between the substrate and the catalytic domain of the ribozyme, resulting in a rearrangement of the substrate helix register into a so-called “shifted” conformation that is critical for substrate binding and activation. We report a 3.3 A crystal structure of the complete ribozyme that reveals the active, shifted conformation of the substrate, docked into the catalytic domain of the ribozyme. Comparison to previous NMR structures of isolated, inactive substrates provides a physical description of substrate remodeling, and implicates roles for tertiary interactions in catalytic activation of the cleavage loop. Similarities to the hairpin ribozyme cleavage loop activation suggest general strategies to enhance fidelity in RNA folding and ribozyme cleavage. |
| Databáze: | OpenAIRE |
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