Genetic characterization of a filament-forming, lipoprotein-deficient mutant of Escherichia coli.

The fam-715 allele of Escherichia coli ST715, previously described as a temperature-sensitive filament former with reduced levels of lipoprotein at the nonpermissive temperature (S. V. Torti and J. T. Park, Nature [London] 263: 323--326, 1976), was mapped at 74 min. This mutation appears to be amber. It is recessive and can be complemented by F' plasmids carrying the wild-type allele or by an F' plasmid carrying an amber suppressor. Isotopic labeling experiments as well as map position differentiate the fam-715 allele from lipoprotein structural gene mutations.