Purification and characterization of Tet(M), a protein that renders ribosomes resistant to tetracycline

• Published in: The Journal of biological chemistry 1991-02, Vol.266 (5), p.2872-2877
• Main Author: Burdett, V
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino Acids - analysis; Electrophoresis, Polyacrylamide Gel; Escherichia coli; Escherichia coli - genetics; Genes, Bacterial; GTP Phosphohydrolase-Linked Elongation Factors - metabolism; Hot Temperature; Hydrolysis; Molecular Sequence Data; Mutation; Peptide Elongation Factor G; Peptide Elongation Factor Tu - genetics; Peptide Elongation Factors - genetics; Plasmids; Repressor Proteins - chemistry; Repressor Proteins - genetics; Repressor Proteins - isolation & purification; ribosomes; Ribosomes - metabolism; Sequence Homology, Nucleic Acid; tetracycline; Tetracycline Resistance - genetics
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)49928-0

The tet(M) tetracycline resistance gene has been found in a wide variety of clinically important bacteria. It has been shown previously (Burdett, V. (1986) J. Bacteriol. 165, 564-569) that the tet(M) gene product mediates resistance at the level of protein synthesis as judged by in vitro assay. Using this assay, large amounts of protein were purified from an Escherichia coli overproducer expressing the gene under control of a T7 promoter. The purified activity consists of a single polypeptide of molecular weight 68,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and was confirmed to be the tet(M) gene product by amino-terminal sequence analysis. Purified Tet(M) has an associated ribosome-dependent GTPase with the specific activity being similar to that of the corresponding activity associated with elongation factor G. Since Tet(M) also displays substantial homology to elongation factor G throughout its length, Tet(M) may function as an analog of this elongation factor.