| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Physiology and Growth |
Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada T2N 1N41
MRC Molecular Biology of Membranes Group, Department of Biochemistry,2 and Department Medical Microbiology and Immunology3, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
Author for correspondence: Raymond J. Turner. Tel: +1 403 220 4308. Fax: +1 403 289 9311. e-mail: turnerr{at}ucalgary.ca
The oxyanion of tellurium, tellurite (
), is toxic to most micro-organisms, particularly Gram-negative bacteria. The mechanism of tellurite toxicity is presently unknown. Many heavy metals and oxyanions, including tellurite, interact with reduced thiols (RSH). To determine if tellurite interaction with RSH groups is involved in the toxicity mechanism, the RSH content of Escherichia coli cultures was assayed. After exposure to tellurite, cells were harvested and lysed in the presence of the RSH-specific reagent 5,5’-dithiobis(2-nitrobenzoic acid). Upon exposure of tellurite-susceptible cells to , the RSH content decreased markedly. Resistance to potassium tellurite (Ter) in Gram-negative bacteria is encoded by plasmids of incompatibility groups IncFI, IncP
, IncHI2, IncHI3 and IncHII, as well as the tehAtehB operon from the E. coli chromosome. When cells harbouring a Ter determinant were exposed to , only a small fraction of the RSH content became oxidized. In addition to tellurite-dependent thiol oxidation, the resistance of E. coli mutants affected in proteins involved in disulfide-bond formation (dsb) was investigated. Mutant strains of dsbA and dsbB were found to be hypersensitive to tellurite (MIC 0·008–0·015 µg K2TeO3 ml-1 compared to wild-type E. coli with MICs of 1–2 µg K2TeO3 ml-1). In contrast, dsbC and dsbD mutants showed no hypersensitivity. The results suggest that hypersensitivity to tellurite is reliant on the presence of an isomerase activity and not the thiol oxidase activity of the Dsb proteins. The results establish that the Ter determinants play an important role in maintaining homeostasis of the intracellular reducing environment within Gram-negative cells through specific reactions with either or thiol:tellurium products.
Keywords: tellurite, resistance, thiol oxidation, heavy metal toxicity, Dsb
Abbreviations: DTNB, 5,5’-dithiobis(2-nitrobenzoic acid); Ter, tellurite resistant; RSH, reduced thiol(s)
This article has been cited by other articles:
|
|
 |
|
  S.-K. Chiang, Y.-C. Lou, and C. Chen NMR solution structure of KP-TerB, a tellurite-resistance protein from Klebsiella pneumoniae Protein Sci., April 1, 2008; 17(4): 785 - 789. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. M. Perez, F. A. Arenas, G. A. Pradenas, J. M. Sandoval, and C. C. Vasquez Escherichia coli YqhD Exhibits Aldehyde Reductase Activity and Protects from the Harmful Effect of Lipid Peroxidation-derived Aldehydes J. Biol. Chem., March 21, 2008; 283(12): 7346 - 7353. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. S. Turner, R. Lo, and P. M. Giffard Inhibition of Staphylococcus aureus Growth on Tellurite-Containing Media by Lactobacillus reuteri Is Dependent on CyuC and Thiol Production Appl. Envir. Microbiol., February 1, 2007; 73(3): 1005 - 1009. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Zawadzka, R. L. Crawford, and A. J. Paszczynski Pyridine-2,6-Bis(Thiocarboxylic Acid) Produced by Pseudomonas stutzeri KC Reduces and Precipitates Selenium and Tellurium Oxyanions. Appl. Envir. Microbiol., May 1, 2006; 72(5): 3119 - 3129. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. J. Harrison, H. Ceri, N. J. Roper, E. A. Badry, K. M. Sproule, and R. J. Turner Persister cells mediate tolerance to metal oxyanions in Escherichia coli Microbiology, October 1, 2005; 151(10): 3181 - 3195. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Hoper, U. Volker, and M. Hecker Comprehensive Characterization of the Contribution of Individual SigB-Dependent General Stress Genes to Stress Resistance of Bacillus subtilis J. Bacteriol., April 15, 2005; 187(8): 2810 - 2826. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Borghese, F. Borsetti, P. Foladori, G. Ziglio, and D. Zannoni Effects of the Metalloid Oxyanion Tellurite (TeO32-) on Growth Characteristics of the Phototrophic Bacterium Rhodobacter capsulatus Appl. Envir. Microbiol., November 1, 2004; 70(11): 6595 - 6602. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Tanaka, A. M. Earl, H. A. Howell, M.-J. Park, J. A. Eisen, S. N. Peterson, and J. R. Battista Analysis of Deinococcus radiodurans's Transcriptional Response to Ionizing Radiation and Desiccation Reveals Novel Proteins That Contribute to Extreme Radioresistance Genetics, September 1, 2004; 168(1): 21 - 33. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. K. Lithgow, E. J. Hayhurst, G. Cohen, Y. Aharonowitz, and S. J. Foster Role of a Cysteine Synthase in Staphylococcus aureus J. Bacteriol., March 15, 2004; 186(6): 1579 - 1590. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. Tantalean, M. A. Araya, C. P. Saavedra, D. E. Fuentes, J. M. Perez, I. L. Calderon, P. Youderian, and C. C. Vasquez The Geobacillus stearothermophilus V iscS Gene, Encoding Cysteine Desulfurase, Confers Resistance to Potassium Tellurite in Escherichia coli K-12 J. Bacteriol., October 1, 2003; 185(19): 5831 - 5837. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Toptchieva, G. Sisson, L. J. Bryden, D. E. Taylor, and P. S. Hoffman An inducible tellurite-resistance operon in Proteus mirabilis Microbiology, May 1, 2003; 149(5): 1285 - 1295. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |
