Structure, flexibility, and mechanism of the Bacillus stearothermophilus RecU holliday junction resolvase
| Autor: | Jie Li, Stephen J. Kelly, Mark J. Jedrzejas, Peter Setlow |
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| Rok vydání: | 2007 |
| Předmět: |
Models
Molecular Tn3 transposon Protein Conformation Molecular Sequence Data Cleavage (embryo) Biochemistry Catalysis Geobacillus stearothermophilus chemistry.chemical_compound Bacterial Proteins X-Ray Diffraction Structural Biology Hydrolase Molecule Amino Acid Sequence Lewis acids and bases Molecular Biology chemistry.chemical_classification Sequence Homology Amino Acid Chemistry fungi Holliday Junction Resolvases Crystallography Enzyme Sequence Alignment DNA |
| Zdroj: | Proteins: Structure, Function, and Bioinformatics. 68:961-971 |
| ISSN: | 0887-3585 |
| DOI: | 10.1002/prot.21418 |
| Popis: | Here we report a high resolution structure of RecU-Holliday junction resolvase from Bacillus stearothermophilus. The functional unit of RecU is a homodimer that contains a “mushroom” like structure with a rigid cap and two highly flexible loops extending outwards. These loops appear to be highly flexible/dynamic, and presumably are directly involved in DNA binding and holding it for catalysis. Structural modifications of both the protein and DNA upon their interaction are essential for catalysis. An Mg2+ ion is present in each of the two active sites in this homodimeric enzyme, and two water molecules are coordinated with each Mg2+ ion. Our data are consistent with one of these water molecules acting as a nucleophile and the other as a general acid. The identities of the general base and general acid involved in catalysis and the Lewis acid that stabilizes the pentacovalent transition state phosphate ion are proposed. A model for the RecU-Holliday junction DNA complex is also proposed and discussed in thecontext of DNA binding and cleavage. Proteins 2007. © 2007 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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