Interaction of theexrandlonGenes inEscherichia coli

Abstract

Strains ofEscherichia colicarrying the genelontypically produced excess capsular polysaccharide, and were sensitive to ultraviolet light (UV) irradiation, thymine starvation, and nalidixic acid, forming long filaments after these treatments. Sensitivity was reduced by a number of posttreatments. In the presence of a second UV sensitivity gene,exr, some of these properties were suppressed: long filaments were not formed, the effect oflonon UV and nalidixic acid sensitivity was greatly reduced, and irradiation posttreatments gave an enhancement of survival characteristic ofexrrather thanlonstrains. Production of capsular polysaccharide was not affected by theexrgene.