Dantley K A, Dannelly H K, Burdett V
Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
J Bacteriol. 1998 Aug;180(16):4089-92. doi: 10.1128/JB.180.16.4089-4092.1998.
Tet(M) protein interacts with the protein biosynthesis machinery to render this process resistant to tetracycline by a mechanism which involves release of the antibiotic from the ribosome in a reaction dependent on GTP hydrolysis. To clarify this resistance mechanism further, the interaction of Tet(M) with the ribosome has been examined by using a gel filtration assay with radioactively labelled Tet(M) protein. The presence of GTP and 5'-guanylyl imido diphosphate, but not GDP, promoted Tet(M)-ribosome complex formation. Furthermore, thiostrepton, which inhibits the activities of elongation factor G (EF-G) and EF-Tu by binding to the ribosome, blocks stable Tet(M)-ribosome complex formation. Direct competition experiments show that Tet(M) and EF-G bind to overlapping sites on the ribosome.
Tet(M)蛋白与蛋白质生物合成机制相互作用，通过一种涉及在依赖GTP水解的反应中使抗生素从核糖体释放的机制，使该过程对四环素产生抗性。为了进一步阐明这种抗性机制，通过使用放射性标记的Tet(M)蛋白进行凝胶过滤分析，研究了Tet(M)与核糖体的相互作用。GTP和5'-鸟苷酰亚胺二磷酸（而非GDP）的存在促进了Tet(M)-核糖体复合物的形成。此外，通过与核糖体结合来抑制延伸因子G（EF-G）和EF-Tu活性的硫链丝菌素，会阻止稳定的Tet(M)-核糖体复合物的形成。直接竞争实验表明，Tet(M)和EF-G结合到核糖体上的重叠位点。
