Regulation of the permeability of the gonococcal cell envelope by the mtr system

Mol Microbiol. 1994 Feb;11(4):769-75. doi: 10.1111/j.1365-2958.1994.tb00354.x.


The mtrR gene of Neisseria gonorrhoeae controls the level of susceptibility to hydrophobic antibiotics and detergents. The mtrR gene was cloned and shown to encode a putative transcriptional repressor. The mtr region was homologous to the envCD and acrAB regions of Escherichia coli, which are also involved in susceptibility to hydrophobic compounds. A homologous repressor protein was encoded by a previously unrecognized open reading frame within both the envCD and acrAB regions. Deletion of mtrR resulted in increased resistance to antibiotics and detergents: the mtrR mutations in two penicillin-resistant clinical isolates resulted in a change of His-105 to Tyr. We propose that the mtrR repressor allows gonococci to regulate the permeability of its cell envelope in response to environmental signals, so that they can grow in the presence of toxic faecal lipids in the rectum as well as in the genital tract.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Base Sequence
  • Carrier Proteins*
  • Cell Membrane Permeability / physiology*
  • Detergents / pharmacology
  • Drug Resistance, Microbial / genetics*
  • Escherichia coli / genetics
  • Escherichia coli Proteins*
  • Ferredoxin-NADP Reductase*
  • Lipoproteins / chemistry
  • Membrane Proteins / chemistry
  • Membrane Transport Proteins
  • Molecular Sequence Data
  • Multidrug Resistance-Associated Proteins
  • Neisseria gonorrhoeae / drug effects
  • Neisseria gonorrhoeae / genetics*
  • Neisseria gonorrhoeae / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Species Specificity


  • AcrA protein, E coli
  • AcrB protein, E coli
  • Bacterial Proteins
  • Carrier Proteins
  • Detergents
  • Escherichia coli Proteins
  • Lipoproteins
  • Membrane Proteins
  • Membrane Transport Proteins
  • Multidrug Resistance-Associated Proteins
  • Repressor Proteins
  • acrF protein, E coli
  • mtrR protein, Neisseria gonorrhoeae
  • methionine synthase reductase
  • Ferredoxin-NADP Reductase

Associated data

  • GENBANK/U14993
  • GENBANK/Z25796
  • GENBANK/Z25797