Suppression of the ptsH mutation in Escherichia coli and Salmonella typhimurium by a DNA fragment from Lactobacillus casei.
A DNA fragment from Lactobacillus casei that restores growth to Escherichia coli and Salmonella typhimurium ptsH mutants on glucose and other substrates of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) has been isolated. These mutants lack the HPr protein, a general component of the PTS. Sequencing of the cloned fragment revealed the absence of ptsH homologues. Instead, the complementation ability was located in a 120-bp fragment that contained a sequence homologue to the binding site of the Cra regulator from enteric bacteria. Experiments indicated that the reversion of the ptsH phenotype was due to a titration of the Cra protein, which allowed the constitutive expression of the fructose operon.
Monedero
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Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, 46100-Burjassot, Valencia, Spain.
Postma
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PW
Pérez-Martínez
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D001426:Bacterial Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005285:Fermentation; D005632:Fructose / Q000378:metabolism; D005816:Genetic Complementation Test; D007780:Lacticaseibacillus casei / Q000235:genetics*; D008969:Molecular Sequence Data; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics*; D012097:Repressor Proteins / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013489:Suppression, Genetic; D056968:Lac Repressors
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D005632:Fructose; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D012097:Repressor Proteins; C489416:FruR protein, E coli; C068837:FruR protein, Bacteria; D056968:Lac Repressors; C030182:phosphocarrier protein HPr