Structural mechanisms of DNA binding and unwinding in bacterial RecQ helicases
| Autor: | Jordan E. Burke, Morgan C. Hill, Kelly A. Manthei, Samuel E. Butcher, James L. Keck |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities DNA Mutational Analysis DNA Single-Stranded Plasma protein binding Crystallography X-Ray Catalysis chemistry.chemical_compound Adenosine Triphosphate ATP hydrolysis Catalytic Domain Escherichia coli Binding site Binding Sites Multidisciplinary Bacteria RecQ Helicases biology Hydrolysis nutritional and metabolic diseases Helicase DNA Biological Sciences enzymes and coenzymes (carbohydrates) Cronobacter Biochemistry chemistry Duplex (building) biology.protein Biophysics Anisotropy Adenosine triphosphate Genome Bacterial Protein Binding |
| Zdroj: | Proceedings of the National Academy of Sciences. 112:4292-4297 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1416746112 |
| Popis: | RecQ helicases unwind remarkably diverse DNA structures as key components of many cellular processes. How RecQ enzymes accommodate different substrates in a unified mechanism that couples ATP hydrolysis to DNA unwinding is unknown. Here, the X-ray crystal structure of the Cronobacter sakazakii RecQ catalytic core domain bound to duplex DNA with a 3′ single-stranded extension identifies two DNA-dependent conformational rearrangements: a winged-helix domain pivots ∼90° to close onto duplex DNA, and a conserved aromatic-rich loop is remodeled to bind ssDNA. These changes coincide with a restructuring of the RecQ ATPase active site that positions catalytic residues for ATP hydrolysis. Complex formation also induces a tight bend in the DNA and melts a portion of the duplex. This bending, coupled with translocation, could provide RecQ with a mechanism for unwinding duplex and other DNA structures. |
| Databáze: | OpenAIRE |
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