title: The glutamate-dependent acid resistance system of Escherichia coli and Shigella flexneri is inhibited in vitro by L-trans-pyrrolidine-2,4-dicarboxylic acid.
abstract: Strains of Escherichia coli K-12, O157:H7, and Shigella flexneri grown to stationary phase in complex unbuffered media can survive for several hours at pH 2.5. This stationary-phase acid resistance phenotype is dependent upon the alternate sigma factor sigmas and the supplementation of either glutamate or glutamine in the acidified media used for acid challenge. Acid resistance under these defined conditions can be inhibited by the glutamate analog L-trans-pyrrolidine-2,4-dicarboxylic acid which blocks uptake of glutamate/glutamine by selective inhibition. The gadC gene, encoding an inner membrane antiporter essential for the expression of acid resistance, could not be detected in other family members of the Enterobacteriacae.
authors.affiliation: Division of Human Immunology, Hanson Institute, IMVS, Adelaide, SA 5000, Australia. scott.waterman@imvs.sa.gov.au
authors.forename: Scott R
authors.initials: SR
authors.lastname: Waterman
authors.forename: P L C
authors.initials: PL
authors.lastname: Small
mesh_terms: D000143:Acids / Q000378:metabolism; D001426:Bacterial Proteins; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D003998:Dicarboxylic Acids / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D018698:Glutamic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology*; D010641:Phenotype; D010957:Plasmids; D011759:Pyrrolidines / Q000494:pharmacology*; D012763:Shigella flexneri / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D012808:Sigma Factor / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D003470:Culture Media; D004269:DNA, Bacterial; D003998:Dicarboxylic Acids; D029968:Escherichia coli Proteins; C491226:GadC protein, E coli; C103589:GadC protein, bacteria; D008565:Membrane Proteins; D014179:Neurotransmitter Uptake Inhibitors; D011759:Pyrrolidines; D012808:Sigma Factor; D005973:Glutamine; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; C083486:pyrrolidine-2,4-dicarboxylic acid