Biphasic excitation by leucine in Escherichia coli chemotaxis.
Leucine concentration jumps (applied by photolysis of inert derivatives) triggered swim or tumble responses in Escherichia coli mutants lacking Tsr or Tar, respectively. Wild-type E. coli bacteria were attracted in spatial assays when the initial leucine concentration difference was 5 to 120 micro M but were repulsed when it was over 0.5 mM. Their responses to concentration jumps confirmed earlier deductions regarding biphasic excitation.
Khan
Shahid
S
Molecular Biology Consortium, Chicago, Illinois 60612, USA. kh01@tigger.uic.edu
Trentham
David R
DR
D002633:Chemotaxis; D004926:Escherichia coli / Q000502:physiology*; D007930:Leucine / Q000494:pharmacology*
D007930:Leucine