The tetracycline efflux protein encoded by the tet(K) gene from Staphylococcus aureus is a metal‐tetracycline/H+ antiporter

FEBS Letters

Yamaguchi, Akihito²  Noguchi, Norihisa¹  Sasatsu, Masanori¹  Sawai, Tetsuo²  Shiina, Yasuko²  Fujihira, Erika² 

[1] Department of Microbiology, Tokyo College of Pharmacy, Hachioji, Tokyo 192-03, Japan;Division of Microbial Chemistry, Faculty of Pharmaceutical Sciences, Chiba University, Chiba 263, Japan

关键词: Tetracycline;    Tetracycline/H+ antiporter;    Antiporter;    Tet K;    Staphylococcus aureus;    MOPS;    3-(N-morpholino)propanesulfonic acid;    TC;    tetracycline;    MINO;    minocycline;    CCCP;    carbonyl cyanide m-chlorophenylhydrazone;   

DOI  :  10.1016/0014-5793(95)00455-I

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The tet(K) gene from Staphylococcus aureus was highly expressed in Escherichia coli by an alteration of its initiation codon from TTG to ATG and its ribosome-binding sequence from GAGG to GGAGG [Noguchi, N. et al. (1994) Biol. Pharm. Bull. 17, 352–355]. The inverted membrane vesicles prepared from the tet(K)-expressing cells showed respiration-dependent [³H]tetracycline transport comparable to the vesicles from the tet(B)-expressing cells. The affinity of Tet(K) vesicles to tetracycline was the same as that of Tet(B) vesicles, whereas the former V _max value was about 60% of the latter one. Contrary to Tet(B) vesicles, Tet(K) vesicles showed no significant minocycline uptake, which was consistent with the low minocycline resistance of the Tet(K)-producing cells. The tetracycline transport mediated by Tet(K) vesicles was coupled with proton transport and the translocation of ⁶⁰Co²⁺ ions as well as in Tet(B) vesicles. This observation indicates that the class K tetracycline resistance determinant from Gram-positive bacteria also encodes a metaltetracycline/H⁺ antiporter that is functionally similar to that encoded by tet(B), although there is a considerable difference in the primary sequences and the putative topologies of these Tet proteins.

【 授权许可】

Unknown