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.
Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
C A
CA
Trieber
N
N
Burkhardt
K H
KH
Nierhaus
D E
DE
Taylor
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