Insights into the architecture and stoichiometry of Escherichia coli PepA-DNA complexes involved in transcriptional control and site-specific DNA recombination by atomic force microscopy
| Autor: | Daniel Charlier, Neel Devroede, Phu Nguyen Le Minh, Dominique Maes, Jan Massant |
|---|---|
| Přispěvatelé: | Microbiology, Structural Biology Brussels, Department of Bio-engineering Sciences, Ultrastructure |
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
DNA
Bacterial Models Molecular Operator Regions Genetic Transcription Genetic Operon pyrimidines Biology Random hexamer carbamoyl phosphate synthase Microscopy Atomic Force arginine synthesis chemistry.chemical_compound Structural Biology Escherichia coli Genetics A-DNA transcriptional regulation Site-specific recombination Binding site Repetitive Sequences Nucleic Acid Recombination Genetic Purr PEPA atomic force microscopy Escherichia coli Proteins site-specific recombination protein-DNA interactions Gene Expression Regulation Bacterial DNA-Binding Proteins chemistry Biochemistry Biophysics Nucleic Acid Conformation aminopeptidase A Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) DNA Plasmids |
| Zdroj: | Vrije Universiteit Brussel Nucleic Acids Research |
| Popis: | Multifunctional Aminopeptidase A (PepA) from Escherichia coli is involved in the control of two distinct DNA transaction processes: transcriptional repression of the carAB operon, encoding carbamoyl phosphate synthase and site-specific resolution of ColE1-type plasmid multimers. Both processes require communication at a distance along a DNA molecule and PepA is the major structural component of the nucleoprotein complexes that underlie this communication. Atomic Force Microscopy was used to analyze the architecture of PepA.carAB and PepA.cer site complexes. Contour length measurements, bending angle analyses and volume determinations demonstrate that the carP1 operator is foreshortened by approximately 235 bp through wrapping around one PepA hexamer. The highly deformed part of the operator extends from slightly upstream of the -35 hexamer of the carP1 promoter to just downstream of the IHF-binding site, and comprises the binding sites for the PurR and RutR transcriptional regulators. This extreme remodeling of the carP1 control region provides a straightforward explanation for the strict requirement of PepA in the establishment of pyrimidine and purine-specific repression of carAB transcription. We further provide a direct physical proof that PepA is able to synapse two cer sites in direct repeat in a large interwrapped nucleoprotein complex, likely comprising two PepA hexamers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|