Oligopeptide transport in Escherichia coli. Specificity with respect to side chain and distinction from dipeptide transport.

摘要: Abstract A lysine auxotroph of Escherichia coli W can use oligopeptides as a source the required amino acid. mutant, defective in oligopeptide transport, was isolated from this strain with resistance to bactericidal action triornithine selection procedure. The triornithine-resistant mutant could no longer grow upon oligopeptides. In an analogous manner glycine lost ability It is concluded that lysine, ornithine, and common transport system, which strain. This conclusion substantiated by studies show competition among these for entry into cell. Tyrosine also compete, they are presumed same system. lack specificity respect side chain taken indication single system may be used therefore marked contrast free acids, several distinct systems required. shown dipeptides predominantly separate although possess limited enter mechanism. contrast, cannot transported specific dipeptide or systems.