Transposon Tn10-dependent expression of the lamB gene in Escherichia coli. Academic Article uri icon


  • Among Tn10 insertions isolated in or near the malB region of Escherichia coli, one (zjb-729::Tn10) mapped between malK and lamB or late in malK and allowed MalT-independent expression of lamB. Tn10-dependent expression of a lamB-lacZ protein fusion was 25% of the expression of the fusion from the malK-lamB operon promoter in malTc constitutive strains. The maltoporin content of a strain carrying this Tn10 was about 20% that of a malTc malB+ strain. Transport of maltose at concentrations of below 10(-6) M was reduced about threefold. When maltoporin was present at about 50% of the level of malTc malB+ strains, maltose transport was largely restored. We conclude that maltoporin is not rate limiting for maltose transport in wild-type cells but becomes rate limiting when the ratio of maltoporin to other maltose transport components is reduced more than twofold.

published proceedings

  • J Bacteriol

author list (cited authors)

  • Brass, J. M., Manson, M. D., & Larson, T. J.

citation count

  • 29

complete list of authors

  • Brass, JM||Manson, MD||Larson, TJ

publication date

  • January 1984