CONSTRUCTION AND PLASMID-BORNE COMPLEMENTATION OF STRAINS LACKING THEEPSILON-SUBUNIT OF THE ESCHERICHIA-COLI F1F0 ATP SYNTHASE

Two strains of Escherichia coli that lack the epsilon subunit of the F 1F0 ATP synthase have been constructed. They are shown to be viable bu t with very low growth yields (28%). These strains can be complemented by plasmids carrying wild-type uncC, but not when epsilon is overprod uced. These results indicate that epsilon is not essential for growth on minimal glucose medium and that the level of its expression affects the assembly of the ATP synthase.