Tn10 generated deletions of the ompB locus of Escherichia coli K12

Abstract We have isolated a set of Tn 10 -generated deletions starting from the distal end of the ompR envZ operon of Escherichia coli K12. Most of the deletions removed both ompR and envZ genes or ended in ompR . These deletions exhibited an OmpC^? OmpF^? phenotype. One deletion removed only part of envZ and the strain was phenotypically OmpC^? OmpF^+/?. This deletion of the distal part of envZ did not affect osmoregulation of ompC . However, ompF osmoregulation appeared reversed. High osmolarity in the growth medium resulted in production of OmpF close to the wild-type level.