Protective Role of tolC in Efflux of the Electron Shuttle Anthraquinone-2,6-Disulfonate
Abstract
Extracellular electron transfer can play an important role in microbial respiration on insoluble minerals. The humic acid analog anthraquinone-2,6-disulfonate (AQDS) is commonly used as an electron shuttle during studies of extracellular electron transfer. Here we provide genetic evidence that AQDS enters Shewanella oneidensis strain MR-1 and causes cell death if it accumulates past a critical concentration. A tolC homolog protects the cell from toxicity by mediating the efflux of AQDS. Electron transfer to AQDS appears to be independent of the tolC pathway, however, and requires the outer membrane protein encoded by mtrB. We suggest that there may be structural and functional relationships between quinone-containing electron shuttles and antibiotics.
Additional Information
© 2002 American Society for Microbiology. Received 29 October 2001; Accepted 17 December 2001. We thank R. Kolter and V. Weaver for providing the E. coli strains used in this study. We also thank M. E. Hernandez, L. Cox, C. Saltikov, A. Lee, and other members of the Newman lab for helpful discussions. Preliminary sequence data were obtained from The Institute for Genomic Research website (http://www.tigr.org). Sequencing of S. oneidensis was accomplished with support from the Department of Energy. This work was supported by a grant from the Office of Naval Research to D.K.N.Attached Files
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Additional details
- PMCID
- PMC134904
- Eprint ID
- 27600
- Resolver ID
- CaltechAUTHORS:20111103-083806661
- Office of Naval Research (ONR)
- Department of Energy (DOE)
- Created
-
2011-11-07Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences