Mutants of Escherichia coli with Altered Surface Properties which are Refractory to Colicin E2, Sensitive to Ultraviolet Light and which can also Show Recombination Deficiency, Abortive Growth of Bacteriophage and Filament Formation

Abstract

SUMMARY: Mutants refractory to colicin E2, previous phenotypic symbol RefII, have now been divided into two major phenotypic groups. CetC mutants in distinction to CetB mutants show increased sensitivity to u.v. and to a detergent (DOC). CetC mutants may also show other properties, including abortive growth of bacteriophage λ and defective division. CetB mutants are refractory to E 2 at 30° but largely sensitive at 37°. CetC mutants are also refractory at 30° but may be either sensitive or completely refractory at 37°. In contrast to Rec− mutants, CetC strains are not sensitive to gamma rays but two mutants show enhanced DNA breakdown after u.v. irradiation. CetC mutants seem defective in a specific membrane component which renders them insensitive to E2 and alteration of which can affect several aspects of DNA metabolism.