| Title | Interaction between the α-Barrel Tip of Vibrio vulnificus TolC Homologs and AcrA Implies the Adapter Bridging Model |
|---|---|
| Author | Seunghwa Lee1, Saemee Song1, Minho Lee1, Soonhye Hwang1, Ji-Sun Kim1, Nam-Chul Ha2*, and Kangseok Lee1* |
| Address | 1Department of Life Science, Chung-Ang University, Seoul 156-756, Republic of Korea, 2Department of Manufacturing Pharmacy, Pusan National University, Busan 609-735, Republic of Korea |
| Bibliography | Journal of Microbiology, 52(2),148-153, 2014, |
| DOI | 10.1007/s12275-014-3578-2 |
| Key Words | AcrA, TolC, TolCV1, TolCV2, multidrug efflux pump |
| Abstract | The AcrAB-TolC multidrug efflux pump confers resistance to Escherichia coli against many antibiotics and toxic compounds. The TolC protein is an outer membrane factor that participates in the formation of type I secretion systems. The genome of Vibrio vulnificus encodes two proteins homologous to the E. coli TolC, designated TolCV1 and TolCV2. Here, we show that both TolCV1 and TolCV2 partially complement the E. coli TolC function and physically interact with the membrane fusion protein AcrA, a component of the E. coli AcrAB-TolC efflux pump. Using site-directed mutational analyses and an in vivo cross-linking assay, we demonstrated that the α-barrel tip region of TolC homologs plays a critical role in the formation of functional AcrAB-TolC efflux pumps. Our findings suggest the adapter bridging model as a general assembly mechanism for tripartite drug efflux pumps in Gram-negative bacteria. |