Genetic characterization and molecular cloning of the tripeptide permease (tpp) genes of Salmonella typhimurium

Abstract

Of the three bacterial peptide transport systems only one, the oligopeptide permease, has been characterized in any detail. We have now isolated Salmonella typhimurium mutants deficient in a second transport system, the tripeptide permease (Tpp), using the toxic peptide alafosfalin. Alafosfalin resistance mutations map at three loci, the gene encoding peptidase A (pepA) and two transport-defective loci, tppA and tppB. Locus tppA has been mapped to 74 min on the S. typhimurium chromosome, cotransducible with aroB, and is a positive regulator of tppB. Locus tppB maps at 27 min in the cotransduction gap between purB and pyrF. We cloned tppB, the structural locus for the tripeptide permease. Two simple methods are described for mapping the location of cloned DNA fragments on the chromosome of S. typhimurium.

Growth of Salmonella typhimurium SL5319 and Escherichia coli F-18 in mouse cecal mucus: role of peptides and iron

“…It should be mentioned that peptides are a good source of nutrition for S. typhimurium, i.e. they are transported and metabolized to free amino acids [14][15][16]. Furthermore, wild-type S. typhimurium can use either L-alanine, t-cysteine, L-proline, or L-serine as the sole source of carbon and nitrogen [17].…”

Peptide transport and chemotaxis in Escherichia coli and Salmonella typhimurium: characterization of the dipeptide permease (Dpp) and the dipeptide‐binding protein

“…The enteric bacteria Escherichia coti and Salmonella typhimurium possess three distinct peptide-transport systems with overlapping substrate specificities (Gibson et al. 1984;Higgins and Gibson.…”

“…fn B. subtills, uptake of peptides via Opp plays an important role in signalling the onset of sporulation (Perego et al, 1991). The tripeptide permease (Tpp) has a more restricted substrate specificity, having highest affinity for hydrophobic tripeptides although it will handle dipeptides to some extent (Gibson et al, 1984), Expression of tpp is induced by anaerobic growth and is positiveiy regulated by the gene products o( ompR and envZ (Jamieson and Higgins. 1984;Gibson et al.…”

Genetic characterization of oligopeptide uptake systems inSinorhizobium meliloti

“…The situation in S. meliloti is different from other bacteria such as Enterobacteria, where oligopeptide transport has been studied more extensively. In E. coli, there are three peptide transport systems (Opp, Dpp, and Tpp) with well-defined and rather exclusive substrate specificities (Gibson et al, 1984;Abouhamad et al, 1991). The interactions among oligopeptide uptake systems at the transcriptional level would be another major difference between S. meliloti and other bacteria such as E. coli.…”