Abstract
The properties of mutants (phenotypic symbol Ref-II) have been examined which adsorb colicin E2 but which are refractory to its action at 30 °C while remaining sensitive at 40 °C. At 30 °C the inhibition of cell division, breakdown of DNA and inhibition of DNA synthesis which occur in sensitive cells are not observed. At 40 °C Ref-II mutants are sensitive to E2 and inhibition of cell division and degradation of DNA take place. Ref-II mutants growing at 40 °C become immediately refractory to E2 after a shift of temperature from 40 to 30 °C. In consequence it is suggested that either the cytoplasmic membrane of the Ref-II mutants undergoes some change in properties at 30 °C, rendering the cells refractory to E2 or that the mutants may produce an altered protein (at 30 °C) the function of which is normally involved in the transmission of the effect of the adsorbed colicin to its lethal site of action.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
