Tauch A, Pühler A, Kalinowski J, Thierbach G
Degussa-Hüls AG, Kantstrabetae 2, Halle-Künsebeck, D-33790, Germany.
Plasmid. 2000 Nov;44(3):285-91. doi: 10.1006/plas.2000.1489.
The complete nucleotide sequence of the tetracycline resistance plasmid pAG1 from the gram-positive soil bacterium Corynebacterium glutamicum 22243 (formerly Corynebacterium melassecola 22243) was determined. The R-plasmid has a size of 19,751 bp and contains at least 18 complete open reading frames. The resistance determinant of pAG1 revealed homology to gram-negative tetracycline efflux and repressor systems of Tet classes A through J. The highest levels of amino acid sequence similarity were observed to the transmembrane tetracycline efflux protein TetA(A) and to the tetracycline repressor TetR(A) of transposon Tn1721 with 64 and 56% similarity, respectively. This is the first time a repressor-regulated tet gene has been found in gram-positive bacteria. A new class of tetracycline resistance and repressor proteins, termed TetA(Z) and TetR(Z), is proposed.
测定了来自革兰氏阳性土壤细菌谷氨酸棒杆菌22243（原称蜜二糖棒杆菌22243）的四环素抗性质粒pAG1的完整核苷酸序列。该R质粒大小为19751 bp，包含至少18个完整的开放阅读框。pAG1的抗性决定簇显示与革兰氏阴性菌中A至J类四环素外排和阻遏系统具有同源性。观察到与跨膜四环素外排蛋白TetA(A)和转座子Tn1721的四环素阻遏蛋白TetR(A)的氨基酸序列相似性最高，分别为64%和56%。这是首次在革兰氏阳性菌中发现阻遏物调节的tet基因。提出了一类新的四环素抗性和阻遏蛋白，称为TetA(Z)和TetR(Z)。
