Abstract
Gram-negative bacteria use tripartite pumps to transport antibacterial drugs and other toxic compounds across the inner and outer membranes, which are separated by the periplasmic space. The TolC protein is an outer membrane factor that participates in the formation of tripartite efflux pumps. The genome of Vibrio vulnificus encodes two E. coli TolC homologs, TolCV1 and TolCV2. Here, we show that both TolCV1 and TolCV2 are involved in the efflux of antimicrobial agents. Deletion of tolCV1 resulted in increased susceptibility of V. vulnificus to chemical detergents, DNA intercalating agents, and antibiotics including erythromycin, novobiocin, and tetracycline, whereas deletion of tolCV2 rendered V. vulnificus more susceptible to the above mentioned antibiotics only. We also observed that tolCV1 deletion resulted in reduced motility of V. vulnificus. Our results indicate active roles for TolCV1 and TolCV2 in the physiology of V. vulnificus.
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Acknowledgments
This study was supported by the Next-Generation BioGreen 21 Program (SSAC, PJ009025), Rural Development Administration, Republic of Korea, and an NRF grant (2011-0028553) funded by the Ministry of Education, Science and Technology, Republic of Korea. It is also partially supported by Chung-Ang University Excellent Student Scholarship in 2014. The authors thank Dr. Minho Lee for his helpful comments.
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Lee, S., Song, S. & Lee, K. Functional Analysis of TolC Homologs in Vibrio vulnificus . Curr Microbiol 68, 729–734 (2014). https://doi.org/10.1007/s00284-014-0537-4
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DOI: https://doi.org/10.1007/s00284-014-0537-4