Ribosomal protection from tetracycline mediated by Tet(O): Tet(O) interaction with ribosomes is GTP-dependent.
Tet(O) mediates tetracycline resistance by protecting the ribosome from inhibition. A recombinant Tet(O) protein with a histidine tag was purified and its activity in protein synthesis characterized. Tetracycline inhibited the rate of poly(Phe) synthesis, producing short peptide chains. Tet(O)-His was able to restore the elongation rate and processivity. 70S ribosomes bound tetracycline with high affinity. Tet(O)-His in the presence of GTP, but not GDP or GMP, reduced the affinity of the ribosomes for tetracycline. Non-hydrolyzable GTP analogs in the presence of the factor were also able to interfere with tetracycline binding. Ribosomes increased the affinity of Tet(O)-His for GTPgammaS. Tet(O), 70S ribosomes and GTPgammaS formed a complex that could be isolated by gel filtration. The GTP conformer is the active form of Tet(O) that interacts with the ribosome. GTP binding is necessary for Tet(O) activity.
Trieber
C A
CA
Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
Burkhardt
N
N
Nierhaus
K H
KH
Taylor
D E
DE
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins; D015870:Gene Expression; D006160:Guanosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D006639:Histidine; D010455:Peptides / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D013752:Tetracycline / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; C083139:Tet O resistance protein, Bacteria; C012001:polyphenylalanine; D006639:Histidine; D006160:Guanosine Triphosphate; D013752:Tetracycline