Localization of the ribosomal protection protein Tet(O) on the ribosome and the mechanism of tetracycline resistance
- Mol Cell. 2001 May;7(5):1037-45. doi: 10.1016/s1097-2765(01)00238-6.
- 1. Howard Hughes Medical Institute, Health Research Inc. at the Wadsworth Center, Empire State Plaza, Albany, NY 12201, USA.
Tet(O) belongs to a class of ribosomal protection proteins that mediate Tetracycline resistance. It is a G protein that shows significant sequence similarity to elongation factor EF-G. Here we present a cryo-electron microscopic reconstruction, at 16 A resolution, of its complex with the E. coli 70S ribosome. Tet(O) was bound in the presence of a noncleavable GTP analog to programmed ribosomal complexes carrying fMet-tRNA in the P site. Tet(O) is directly visible as a mass close to the A-site region, similar in shape and binding position to EF-G. However, there are important differences. One of them is the different location of the tip of domain IV, which in the Tet(O) case, does not overlap with the ribosomal A site but is directly adjacent to the primary Tetracycline binding site. Our findings give insights into the mechanism of Tetracycline resistance.