Another gene affecting sexual expression of Escherichia coli

Abstract

The authors have examined the relationship between two chromosomal mutations of E. coli K-12, fexA (0 min) and fexB (85 min), in regulating expression of F sex factor. Together, fexA and fexB exert a pleiotropic effect on the expression of the F tra genes. F pilus synthesis, conjugal donor activity, and surface exclusion activity are all inhibited in the fexA fexB mutant. Either fex mutation alone is cryptic.