ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
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 translations! fusion to maIE 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.1996.tb02654.x
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