Localization of the Ribosomal Protection Protein Tet(O) on the Ribosome and the Mechanism of Tetracycline Resistance

• Published in: Molecular cell 2001-05, Vol.7 (5), p.1037-1045
• Main Authors: Spahn, Christian M.T., Blaha, Gregor, Agrawal, Rajendra K., Penczek, Pawel, Grassucci, Robert A., Trieber, Catharine A., Connell, Sean R., Taylor, Diane E., Nierhaus, Knud H., Frank, Joachim
• Format: Article
• Language: English
• Subjects: Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Bacterial Proteins - pharmacology; Binding Sites; Carrier Proteins; Cryoelectron Microscopy; Escherichia coli; Escherichia coli - chemistry; Models, Molecular; Molecular Conformation; Protein Biosynthesis - drug effects; Protein Structure, Tertiary; Ribosomes - chemistry; Ribosomes - metabolism; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - metabolism; RNA-Binding Proteins - pharmacology; Tet(O) protein; TetO protein; Tetracycline Resistance - physiology; tRNA fMet
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/S1097-2765(01)00238-6

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 Å 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.