Sequence homology between the tetracycline-resistance determinants of Tn10 and pBR322

Toai T. Nguyen, Kathleen Postle, Kevin P. Bertrand

Research output: Contribution to journalArticlepeer-review

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The Tn10 tetracycline resistance gene, tetA, encodes a tetracycline-inducible protein with an apparent Mr of 36 × 103. We have determined the nucleotide sequence of the Tn10 tetA gene. The extent of the tetA gene was determined by analysis of amino-terminal and carboxy-terminal deletion mutants. We conclude that a single Tn10 gene, the tetA gene, is sufficient to confer tetracycline resistance, The predicted Mr of the tetA protein is 43.2 × 103. The sequence homology between the Tn10 tetA gene and pBR322 tetracycline resistance determinant (49% nucleotide homology, 44% amino acid homology) indicates that these phenotypically distinct tetracycline-resistance determinants must have evolved from a common ancestral sequence. The markedly hydrophobic character of the predicted amino acid sequences of the Tn10 tetA and pBR322 tet-coded proteins suggests that a substantial portion of these proteins may be embedded within the cytoplasmic membrane.

Original languageEnglish (US)
Pages (from-to)83-92
Number of pages10
Issue number1
StatePublished - Nov 1983

All Science Journal Classification (ASJC) codes

  • Genetics


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