The ABC transporter family efflux pump PvdRT‐OpmQ of Pseudomonas putida KT2440: purification and initial characterization

• Published in: FEBS letters Vol. 597; no. 10; pp. 1403 - 1414
• Main Authors: Stein, Nicola Victoria, Eder, Michelle, Brameyer, Sophie, Schwenkert, Serena, Jung, Heinrich
• Format: Journal Article
• Language: English
• Published: England 01-05-2023
• Subjects: ABC transporter; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological Transport; ligand binding; membrane protein purification; Periplasm - metabolism; Pseudomonas putida - genetics; Pseudomonas putida - metabolism; pyoverdine; siderophore; Siderophores; tripartite efflux pump; membrane protein purification; tripartite efflux pump; pyoverdine; ABC transporter; ligand binding; siderophore
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1002/1873-3468.14601

Tripartite efflux systems of the ABC‐type family transport a variety of substrates and contribute to the antimicrobial resistance of Gram‐negative bacteria. PvdRT‐OpmQ, a member of this family, is thought to be involved in the secretion of the newly synthesized and recycled siderophore pyoverdine in Pseudomonas species. Here, we purified and characterized the inner membrane component PvdT and the periplasmic adapter protein PvdR of the plant growth‐promoting soil bacterium Pseudomonas putida KT2440. We show that PvdT possesses an ATPase activity that is stimulated by the addition of PvdR. In addition, we provide the first biochemical evidence for direct interactions between pyoverdine and PvdRT.
The present study provides first insights into the binding of pyoverdine, the main siderophore of Pseudomonas putida KT2440, to its proposed ATP‐binding cassette transporter (ABC transporter), PvdRT‐OpmQ. Both the transporter and adapter components were purified and solubilized in detergents, and ATPase activity was measured. The data suggest that pyoverdine binds to the ABC transporter and that enzyme activity depends on the adapter protein.