Regulation of the permeability of the gonococcal cell envelope by the mtr system.
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.
Pan
W
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Microbial Genetics Group, School of Biological Sciences, University of Sussex, Falmer, Brighton, UK.
Spratt
B G
BG
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D001483:Base Sequence; D002352:Carrier Proteins; D002463:Cell Membrane Permeability / Q000502:physiology*; D003902:Detergents / Q000494:pharmacology; D004352:Drug Resistance, Microbial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005287:Ferredoxin-NADP Reductase; D008074:Lipoproteins / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009344:Neisseria gonorrhoeae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D001426:Bacterial Proteins; D002352:Carrier Proteins; D003902:Detergents; D029968:Escherichia coli Proteins; D005287:Ferredoxin-NADP Reductase; D008074:Lipoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012097:Repressor Proteins; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli; C071960:acrF protein, E coli; C087450:mtrR protein, Neisseria gonorrhoeae; C111241:methionine synthase reductase