This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by McMurry, L M Articles by Levy, S B Search for Related Content PubMed PubMed Citation Articles by McMurry, L M Articles by Levy, S B

 Previous Article  |  Next Article 

J Bacteriol. 1992 October; 174(19): 6294-6297

research-article

Decreased function of the class B tetracycline efflux protein Tet with mutations at aspartate 15, a putative intramembrane residue.

Department of Molecular Biology, Tufts University School of Medicine, Boston, Massachusetts 02111.

ABSTRACT

The aspartate 15 residue within the first predicted intramembrane helix of the tetracycline efflux protein Tet has been conserved in four tetracycline resistance determinants from gram-negative bacteria. Its replacement in class B Tet by tyrosine, histidine, or asparagine resulted in a 60 to 85% loss of tetracycline resistance and a similar loss of tetracycline-proton antiport. The tyrosine and histidine substitutions lowered the Vmax of the efflux system by some 90% but did not alter the Km. The asparagine substitution raised the Km over 13-fold, while the Vmax was equal to or greater than that of the wild type. Therefore, although the nature of its role is unclear, aspartate 15 is important for normal Tet function.

This article has been cited by other articles:

• Sapunaric, F. M., Levy, S. B. (2005). Substitutions in the interdomain loop of the Tn10 TetA efflux transporter alter tetracycline resistance and substrate specificity. Microbiology 151: 2315-2322 [Abstract] [Full Text]  
• Joseph, P., Ratnayake-Lecamwasam, M., Sonenshein, A. L. (2005). A Region of Bacillus subtilis CodY Protein Required for Interaction with DNA. J. Bacteriol. 187: 4127-4139 [Abstract] [Full Text]  
• McMurry, L. M., Aldema-Ramos, M. L., Levy, S. B. (2002). Fe2+-Tetracycline-Mediated Cleavage of the Tn10 Tetracycline Efflux Protein TetA Reveals a Substrate Binding Site near Glutamine 225 in Transmembrane Helix 7. J. Bacteriol. 184: 5113-5120 [Abstract] [Full Text]  
• Schnabel, E. L., Jones, A. L. (1999). Distribution of Tetracycline Resistance Genes and Transposons among Phylloplane Bacteria in Michigan Apple Orchards. Appl. Environ. Microbiol. 65: 4898-4907 [Abstract] [Full Text]  
• Nelson, M. L., Levy, S. B. (1999). Reversal of Tetracycline Resistance Mediated by Different Bacterial Tetracycline Resistance Determinants by an Inhibitor of the Tet(B) Antiport Protein. Antimicrob. Agents Chemother. 43: 1719-1724 [Abstract] [Full Text]  
• Jewell, J. E., Orwick, J., Liu, J., Miller, K. W. (1999). Functional Importance and Local Environments of the Cysteines in the Tetracycline Resistance Protein Encoded by Plasmid pBR322. J. Bacteriol. 181: 1689-1693 [Abstract] [Full Text]  
• Kim, M.-H., Lu, M., Lim, E.-J., Chai, Y.-G., Hersh, L. B. (1999). Mutational Analysis of Aspartate Residues in the Transmembrane Regions and Cytoplasmic Loops of Rat Vesicular Acetylcholine Transporter. J. Biol. Chem. 274: 673-680 [Abstract] [Full Text]  
• Guffanti, A. A., Cheng, J., Krulwich, T. A. (1998). Electrogenic Antiport Activities of the Gram-positive Tet Proteins Include a Na+(K+)/K+ Mode That Mediates Net K+ Uptake. J. Biol. Chem. 273: 26447-26454 [Abstract] [Full Text]  
• Merickel, A., Rosandich, P., Peter, D., Edwards, R. H. (1995). Identification of Residues Involved in Substrate Recognition by a Vesicular Monoamine Transporter. J. Biol. Chem. 270: 25798-25804 [Abstract] [Full Text]  
• Yerushalmi, H., Mordoch, S. S., Schuldiner, S. (2001). A Single Carboxyl Mutant of the Multidrug Transporter EmrE Is Fully Functional. J. Biol. Chem. 276: 12744-12748 [Abstract] [Full Text]