title: The utilization of prolyl peptides by Escherichia coli.
abstract: Peptides that have an N-terminal proline residue are taken up by Escherichia coli and are degraded by intracellular peptidases. A mutant that is unable to transport oligopeptides with N-terminal alpha-amino acids is also unable to transport the peptides with N-terminal proline. Dipeptides and oligopeptides can prevent the uptake of the corresponding prolyl peptides and the converse competitive interactions are also observed. Although the peptide alpha-amino group is essential to the process of peptide transport, the results with the prolyl peptides indicate that the dipeptide and oligopeptide permeases can handle peptides with either an alpha-amino or alpha-imino group.
mesh_terms: D001693:Biological Transport, Active; D004151:Dipeptides / Q000378:metabolism; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism*; D005998:Glycine / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D009154:Mutation; D010447:Peptide Hydrolases / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D011392:Proline / Q000378:metabolism*
chemical_list: D004151:Dipeptides; D026901:Membrane Transport Proteins; D010455:Peptides; D010649:Phenylalanine; D011392:Proline; D010447:Peptide Hydrolases; D008239:Lysine; D005998:Glycine