A Bacterial Arginine-Agmatine Exchange Transporter Involved in Extreme Acid Resistance
| Autor: | Yiling Fang, Christopher Miller, Ludmila Kolmakova-Partensky |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Agmatine
Amino Acid Transport Systems Arginine Decarboxylation Antiporter Biology Bacterial Physiological Phenomena medicine.disease_cause Models Biological Biochemistry Antiporters Catalysis chemistry.chemical_compound Escherichia coli medicine Molecular Biology Micelles Escherichia coli Proteins Isothermal titration calorimetry Cell Biology Hydrogen-Ion Concentration Lipids Dissociation constant Cross-Linking Reagents chemistry Glutaral Liposomes Efflux Dimerization Protein Binding |
| Zdroj: | Journal of Biological Chemistry. 282:176-182 |
| ISSN: | 0021-9258 |
| Popis: | The arginine-dependent extreme acid resistance response of Escherichia coli operates by decarboxylating arginine. AdiC, a membrane antiporter, catalyzes arginine influx coupled to efflux of the decarboxylation product agmatine, effectively exporting a proton in each turnover. Using the adiC coding sequence under control of a tetracycline promoter in an E. coli vector, we expressed and purified the transport-protein with a yield of approximately 10 mg/liter bacterial culture. Glutaraldehyde cross-linking experiments indicate that the protein is a homodimer in detergent micelles and lipid membranes. Purified AdiC reconstituted into liposomes exchanges arginine and agmatine in a strictly coupled, electrogenic fashion. Kinetic analysis yields K(m) approximately 80 microm for Arg, in the same range as its dissociation constant determined by isothermal titration calorimetry. |
| Databáze: | OpenAIRE |
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