A new gene responsible for an energy-transducing system in Escherichia coli

A mutant strain (ttr-3) of Escherichia coli was originally isolated as a strain resistant to tributyltin exhibiting temperature-sensitive depressions of growth and ATP synthesis on succinate plates at 42 degrees C. The ttr gene was mapped between the pyrE and dnaA genes (in the 82-83 min region) on the chromosome by P1-transduction experiments. Comparison of proline transport and oxygen uptake by membrane vesicles of the wild-type transductant and the mutant (ttr-3) transductant showed that membrane vesicles of the mutant exhibited temperature-sensitive decrease of proline transport and increase of oxygen uptake at the restrictive temperature (42 degrees C), compatible with depression of growth of the mutant at this temperature. Therefore, the ttr gene seems to code for some factor involved in the respiratory chain that is present in the inner membrane of Escherichia coli.