In vitro disassembly and reassembly of an ABC transporter, the histidine permease
| Autor: | Pei-Qi Liu, Giovanna Ferro-Luzzi Ames |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Multidisciplinary
Protein Conformation Membrane transport protein Permease Protein subunit ATPase Biological Transport Active Membrane Transport Proteins ATP-binding cassette transporter Periplasmic space Biological Sciences Biology Bacterial Proteins Biochemistry ATP hydrolysis Escherichia coli biology.protein Amino Acid Transport Systems Basic ATP-Binding Cassette Transporters Dimerization Integral membrane protein Phospholipids |
| Zdroj: | Proceedings of the National Academy of Sciences. 95:3495-3500 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.95.7.3495 |
| Popis: | The membrane-bound complex of the Salmonella typhimurium periplasmic histidine permease, a member of the ABC transporters (or traffic ATPases) superfamily, is composed of two integral membrane proteins, HisQ and HisM, and two copies of an ATP-binding subunit, HisP. The complex hydrolyzes ATP upon induction of the activity by the liganded soluble receptor, the periplasmic histidine-binding protein, HisJ. Here we take advantage of the modular organization of this system to show that the nucleotide-binding component can be stripped off the integral membrane components, HisQ and HisM. The complex can be reconstituted by using the HisP-depleted membranes containing HisQ and HisM and pure soluble HisP. We show that HisP has high affinity for the HisP-depleted complex, HisQM, and that two HisP molecules are recruited independently of each other for each HisQM unit. The in vitro reassembled complex has entirely normal properties, responding to HisJ and ATPase inhibitors with the same characteristics as the original complex and in contrast to those of soluble HisP. These results show that HisP is absolutely required for ATP hydrolysis, that HisQM cannot hydrolyze ATP, that HisP depends on HisQM to relay the inducing signal from the soluble receptor, HisJ, and that HisQM regulates the ATPase activity of HisP. We also show that HisP changes conformation upon exposure to phospholipids. |
| Databáze: | OpenAIRE |
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