title: Escherichia coli K-12 mutants altered in the transport systems for oligo- and dipeptides.
abstract: Two mutants of Escherichia coli K-12, defective in the oligopeptide and dipeptide transport system, are described. A mutant defective in the oligopeptide transport system (opp-1) was isolated as resistant to the inhibitory action of triornithine; this mutant is also resistant to glycylglycylvaline and does not concentrate (14)C-glycylglycylglycine, although it is still as sensitive as the parental strain to glycylvaline and valine. Starting from the opp-1 strain, a mutant defective also in the dipeptide transport system (dpp-1) was isolated; this mutant is resistant to the inhibitory action of glycylvaline, valylleucine, and leucylvaline and does not concentrate (14)C-glycylglycine, although it is still as sensitive as the parental strain to valine. The apparent kinetic constants for oligopeptide and dipeptide transport were measured. The opp marker is co-transducible with trp at 27 min on the E. coli genetic map. The dpp locus is separated from opp and is located between proC (10 min) and opp.
mesh_terms: D002250:Carbon Radioisotopes; D002874:Chromosome Mapping; D003470:Culture Media; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D005998:Glycine / Q000378:metabolism; D009154:Mutation; D009842:Oligopeptides / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D013194:Staining and Labeling; D013997:Time Factors; D014633:Valine / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D003470:Culture Media; D009842:Oligopeptides; D010455:Peptides; D014633:Valine; D005998:Glycine