An elongation factor Tu (EF-Tu) resistant to the EF-Tu inhibitor GE2270 in the producing organism Planobispora rosea.
Using a cell-free protein-synthesis system, we have established that the elongation factor (EF) Tu (EF-Tu) of the actinomycete Planobispora rosea, the producer of the thiazolyl peptide GE2270, a specific EF-Tu inhibitor, is highly resistant to its own antibiotic, while it is completely inhibited by kirromycin, which is another inhibitor of this factor. P. rosea was found to possess a single tuf gene, located between fus and rpsJ, encoding other components of the protein-synthesis machinery. The P. rosea tuf gene was expressed as a translational fusion to malE in Escherichia coli, and the resulting EF-Tu with an N-terminal Gly-Met extension was able to promote poly(U)-directed poly(Phe) synthesis in cell-free systems. This activity was not affected by GE2270, and the recombinant protein was incapable of binding the antibiotic, indicating that the P. rosea EF-Tu is intrinsically resistant to this inhibitor. Inspection of the translated tuf sequence revealed a number of amino acid substitutions in highly conserved positions. These residues, which are likely to be involved in conferring GE2270 resistance, map in EF-Tu domain II, as do the only two known mutations conferring resistance to this class of thiazolyl peptides in Bacillus subtilis.
Lepetit Research Centre, Gerenzano, Italy.
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D018528:ATP-Binding Cassette Transporters; D000192:Actinomycetales / Q000502:physiology*; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D058619:Maltose-Binding Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D010444:Peptide Elongation Factor Tu / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D010456:Peptides, Cyclic / Q000494:pharmacology*; D033902:Periplasmic Binding Proteins; D011728:Pyridones / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013844:Thiazoles / Q000494:pharmacology
D018528:ATP-Binding Cassette Transporters; D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D010456:Peptides, Cyclic; D033902:Periplasmic Binding Proteins; D011728:Pyridones; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D013844:Thiazoles; C461599:maltose transport system, E coli; D010444:Peptide Elongation Factor Tu; C068122:GE 2270 A; C008536:mocimycin