Chromosomal location of a gene (nmpA) involved in expression of a major outer membrane protein in Escherichia coli.

The phenotypic expression of protein E, a recently described major outer membrane protein, is associated with a mutation at a locus on the Escherichia coli chromosome that we call nmpA. nmpA is located between rbsK and uncA at 82.7 min on the E. coli linkage map. The nmpA locus is also the site of the mutations which lead to the formation of major outer membrane proteins Ic or e. It is likely proteins E, Ic, and e are closely related or identical. The mutant nmpA allele is dominant.